Window Review Blog
The Great Debate
Feb. 21, 2012
Re-View often gets dragged into the debate on what is the proper scope of work for historic windows. It is often a heated subject that is vented out at tradeshows, meetings, and internet chat groups. As is the case with any good brawl, the emotions often run high from all constituents.
Anyone who has been involved in a project with historic fenestration has had to confront the question of what strategy to adopt concerning the windows. There are two opposing camps that best define this debate on historic windows. The following definitions of the window manufacturer and the tree hugger are done in the extreme for dramatic effect:
The Window Manufacturer: This group has one goal and that is to sell more windows. Profitability of the corporation and market share are paramount. As a rule, this group is more interested in increasing volume than doing what is right for the building. Attention to historic detail, performance, and quality are only considered if they are deemed contributory to the bottom line. The use of attractive photographs, slanted test results, and mass advertising has enabled this group to establish a strong influence.
The Tree Hugger: The biggest regret for this group is that they didn’t make it to the Woodstock concert back in 1969. They are extremely passionate about retaining historic fabric on a preservation project. All means, methods, and materials must be focused on restoring the window system back to its original form. Any deviation from that course is an abomination. Since this group is so fragmented and lacks the sex appeal or the marketing budgets of the manufacturers, they often remain the soft voice in the debate. If one listens to their common sense position on the subject, however, the message is very compelling and powerful.
So if you are an owner, architect, or general contractor how do you make sense of these diametrically opposed viewpoints concerning the subject? Do you replace your historic windows with new units, or do you restore every element back to its original state? The answer to that question depends on a number of factors such as the historic significance of the property, the use of the building, the budget, and the construction schedule. It also depends upon where the owner and architect land on the debate spectrum.
I am a firm believer that it helps to have input that is void of emotion to assist in determining an opinion on this subject. Unfortunately, there are few unbiased studies that exist on the topic. If you ask the manufacturers for data, they will produce internal test results that allege 74% energy savings with their products and claims of no future maintenance. If you ask the tree huggers, they will argue superior performance through complete restoration combined with a storm window and pull out the social responsibility card.
We have seen an independent study that is worthy of consideration. Robin E. Whitehurst and Susan Turner of Bailey Edward authored a study in 2009 that evaluated different treatments for windows at Lincoln Hall at the University of Illinois. The study compared replacing the windows with aluminum clad wood units, restoring the existing windows and retrofitting them with insulated glass, and adding a storm window to a repaired window.
The three courses of action were evaluated on energy performance, initial cost, maintenance costs, life cycle costs, and effects on the historic fabric. The study makes for good reading if you are wrestling with how to attend to historic windows on your project.
You can access the study through the following link:
http://www.illinoishistory.gov/ps/Lincoln%20Hall%20Window%20Life%20Cycle%20Study%202008%20%20Univ.%20of%20Illinois%20at%20Urbana%20Champaign.pdf
Do You Have the Energy
Nov. 10, 2011
The construction industry has been sold a story that historic windows are energy hogs that are largely responsible for the depletion of fossil fuels in the United States. I am not going to dive into that debate at the moment because I am not in the mood to mud wrestle with the major window manufacturers. This post is going to address the different options you have in converting historic wood or steel windows into energy efficient systems. Re-View has been successful in upgrading the energy energy performance of 100+ year old windows to meet or even exceed modern manufactured windows.
The most common method known in the construction industry for enhancing the performance of an old single-paned window is the use of a storm window. Storm windows have come a long way in the last 15 years. Instead of the flimsy mill-finished behemoths of yesteryear as pictured below, the new storm window designs are made of extruded aluminum and have low profile sash and frames so they don't distract from the window. You can match arches at the window heads and even find storms that have bent glass to match the radius of a curved window. There are also many different methods of attaching the storms to facilitate simple cleaning and maintenance. Removable fasteners, operable clips, and magnetic mounting techniques are used to eliminate the albatross effect of a traditional storm window.
Although storm windows sound very simple in concept, you can run into problems. The first is to make certain you are measuring the window opening in the same manner as the manufacturer. You may also need to take several width measurements for tall windows to adjust for irregularities. We have seen many installations where the storm just didn't fit the opening. It is also critical to allow for some ventilation between the storm window and the existing window system. We had a project a couple of years ago where moisture caught in the wall cavity caused condensation between the storm and the primary window. If you are doing a residential project, it is essential to pay attention to egress codes; fixed storms or a design that limits the opening size may not be a possibility.
Re-View is currently engineering an energy panel system that puts a typical storm window on steroids. Can you imagine a historic wood or steel window with an R Value approaching 7 or even higher? Our product has a frame made of a combination of aluminum and wood with high-efficiency insulated glass with multiple Low E coatings. By combining aluminum with wood, we are able to increase the structural characteristics while we advance the thermal performance of the framing material. We also enable the customer to apply custom finishes by either staining the wood or matching any custom interior enamel finish. We can fabricate the system in virtually any wood species so matches to interior millwork will be seamless as evidenced by the picture below of one of our installation in a historic train depot. Please contact us to discuss how such a revolutionary technology might be incorporated into your next project.
Another way to improve the energy performance of historic windows is to convert the single pane glass to insulated glass during the restoration process. We haven't found many steel windows that have the required depth to enable such a conversion, but wood windows are ideal candidates. On a typical wood window sash that is 1-3/4" thick, we are able to remove approximately 1/4" from the interior profile of the window to allow for the thicker glass. (See picture below) The glass is glazed with a mahogany stop that is completely primed on all sides and both ends prior to installation. Don't be tempted to use glazing compound like the original single pane installation since the compound is incompatible with the insulated glass seal. This will only accelerate seal failure of the glass. The wood stop is milled to a profile that replicates the glazing compound so you can't tell the difference between a stop glaze and the old compound glaze.
Insulated glass can also be introduced into a historic window system by fabricating an exact replica of the original sash with the exception of the insertion of insulated glass. The new sash would share the design of the original in all aspects such as size, shape, profiles, and joinery. We are able to include up to 5/8" insulated glass into a 1-3/4" thick replicated window. The sash is then hung into the original window frame using the existing pulleys and augmenting the weights to balance the heavier glass. Re-View is one of the largest historic wood window manufacturers in the country, using virtually any wood species and glass type available. The picture below shows a radius or bent sash replica we fabricated for a Governor's mansion project.
Finally, there are ways to incorporate modern weather stripping into the historic window design without changing the form or function. We use what is called fin seal in hidden areas such as the edge of the sash or the back side of the sash stop. Fin seal does an excellent job of eliminating air infiltration. We also use polyethylene clad, urethane foam seals at critical areas such as the rails of a double hung window or the perimeter of the frame of a casement as pictured below. All of these weather strips are invisible when the window is closed. In addition to the modern weather strips, we are still believers in some of the traditional metal weather seals since they last forever and are effective performers. We have achieved independently tested air infiltration rates that are actually superior to the published rates from the major window manufacturers. 
As you can see from the above, there are many options to advancing the energy performance of historic wood and steel windows. All it takes is a little time plotting a strategy that works best for your window design, targeted performance values, use of window, and budget.
Don't Do This At Home
Oct. 04, 2011
Most project construction documents and specifications outline all of the processes and materials to be utilized in the window restoration scope of work. The construction team focuses on what has to happen to make for a successful project. In this business climate where bids for the same scope of work can vary by 100% or greater, it is also important to focus on what definitely cannot happen on a project. The last thing you need to happen is for the low bidder to work substandard materials and abbreviated means and methods into your project. The following two projects we surveyed last week have some excellent examples of what should never happen on a window restoration project.
The first project involved a wood double hung window restoration where the existing frame, trim, and sash were to be restored, sash to be reglazed, and the entire system to be painted on the exterior and stained on the interior. The sash were to be set as fixed in the opening. Typically the window sash would be removed to be restored, glazed, and finished in an offsite environment. The frames would be abated in place and finished in the field. We discovered the following problems on this project:
The restoration contractor left the lifts, lock, and pull down hardware on the sash when it was stripped. The sash was then sanded without removing these elements. You can see by the picture below how the lift was sanded during this faulty process, causing scratch marks. You can also see evidence of stain that was not removed around the perimeter of the hardware since it was impossible to contact with sand paper.
Converting a historic wood window sash from single pane to insulated glass is more complicated than it looks. The engineering of the muntins, the glazing materials, and the glass has to work in concert. If the glass size is incorrect or the glazing stops are installed improperly, you can have an unsightly sash that will leak and have seal failure in a matter of years. Take a close look at this IG conversion we ran across last week. The restoration contractor failed to use low profile spacer bars in the insulated glass so 1/8" or greater of the black spacer bar sealant is visible on both the interior and exterior. This black shadow could have been eliminated by using the proper type of glass and by measuring each lite with precision. At Re-View we measure each glass lite with a laser.
One of the most overlooked processes on a window restoration project is the application of finishes. The proper selection of finishes, prep work of the substrate, and application techniques are key to a good finish. Add in considerations like relative humidity, exposure to the sun, and temperature variances and you can see why it is challenging to achieve a quality paint job. Take a look at the picture below of a frame that was restored and finished only seven years ago. The contractor failed to neutralize the strippers used to remove the original finishes. This improper neutralization caused catastrophic failure of the new finishes. The result is a seven year old restoration project that looks worse than the windows did before they were refurbished.
Please feel free to contact Re-View to discuss historic window issues. One thing we like about this business is that we are always learning as well.
One Butt to Kick
Aug. 17, 2011
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Scheduling the different trades is always a challenge and when you combine an abatement, restoration, glazing, and painting subcontractor with a window manufacturer, there is plenty of potential for serious delays. Many of these companies are very small specialty shops that can easily get bogged down with other work that will inhibit their ability to perform on your project. It is very important to line out the schedules of all of the trades and get a commitment from all of the players. It is also important to select players who have the capacity to meet the respective deadlines. Check backlogs of work and visit the facilities of each sub to verify availability. -
It is critical that the various trades understand their scope of work and how it affects the trades that follow. The last thing you need is to have an abatement contractor tear up a wood window in an attempt to remove lead-based paint. We have seen many projects where one trade contributes cost and delays to the subs who follow because they either don't care or don't understand the big picture. -
Quality control at each step becomes a major burden in managing multiple trades. You will have big problems if you rely on each subcontractor to monitor their own work and fail to regularly check on their progress. We have seen problems with failures to neutralize strippers, excessive use of epoxies, insufficient paint mil thickness, faulty glazing, or sloppy carpentry. It is amazing how even a small quality control problem can derail an entire project. -
The instability of our current economic environment also places a risk factor in managing multiple subcontractors to perform a window restoration project. As a consequence, we have seen a dramatic increase in bonding requirements for basic preservation projects. Many of the small specialty subcontractors in this business can't bond their work, increasing the risk for the general contractor. -
Often window restoration projects are awarded as bid packages where the lead contractor strings together his subs and bids the package to the construction manager. This type of project management can become expensive since the lead contractor is marking up all of the subs who have individual G&A and profit markups in their price as well. There really isn't room for multiple markups in this economy. -
I must give my economics professors of the past a little recognition and mention the opportunity costs for a general contractor to manage multiple subcontractors on a window restoration project. All of the time spent on scheduling, quality control, and scope conflict could be spent on other work associated with the project. Windows shouldn't occupy a large percentage of the building team's time.
For many of the reasons outlined above, we are seeing an increase in specifications that demand a single company to manage all historic window activities. These projects are referred to as single source responsibility or turnkey scopes of work. The people at Re-View refer to this as our "One Butt to Kick" philosophy.
Eleven years ago, Re-View recognized the benefit of becoming a turnkey operation. We grew weary of having to deal with the problems and challenges of our many subcontractors. When you enter into a business contract with another company, you are getting into bed with this organization for the duration of the project. You are buying into the ownership and employees of all your subs. We found that problems and delays caused by subcontractors, manufacturers, and suppliers became our greatest challenge to successfully completing a project. To compound our ordeal, there seem to be very few companies that have experience in this field. It isn't like you can quickly change horses when one of your subs is swamped with other work or goes out of business. That is a big reason why the bonding companies seem to have a distaste for this industry.Re-View has successfully developed competencies in abatement, field and shop restoration of wood and steel windows, manufacturing of historically correct wood windows, window finishing, and union field installation. Since we control the resources associated with these disciplines we can more effectively manage scheduling and produce better and more consistent quality. The ability to provide a turnkey package also enables our company to become better at everything we do. For instance, our ability to manufacture historic window replicas is improved when we understand the complexities of window installation.
Historic Ballistic Window Hits the Target
May. 10, 2011
Re-View was presented with the challenge of how to create a double hung window that carries a UL 752, Bullet Resisting Equipment, Level 8 rating.Our craftsmen had already restored hundreds of historic wood double hung windows on this project in different phases. We essentially had to reconstruct the original wood windows after they had been butchered by a previous window replacement project decades ago. Our carpenters rebuilt the frames in the field and then installed custom mahogany sash fabricated by the Re-View plant. The sash matched the original design except for the inclusion of energy efficient insulated glass. Since the average window was 56 inches wide by 150 inches tall, they were striking in a monumental way.
Re-View responded with a very unique design. The frame consisted of a 1 inch thick solid steel bar that was 8 inches wide. The frame parts were coped and butted and fully welded at the corners. Each simulated sash member was constructed of 2 inch square steel tubes with 1/2 inch plates covering the exterior surface and 1/4 inch plates covering the interior. The simulated meeting rail was constructed of solid steel with a machined glazing pocket. All connections were coped, butted, and welded. The glass was 2 inch thick laminated security glazing with a UL rating at Level 8. An interior of 9/16 inch thick African mahogany wood veneer covered all interior surfaces to give the window the same wood stained look as all of the original wood windows. We even installed fake pulleys, locks, and sash lifts to make the replica look like the originals.
Re-View tested the component pieces of the window design at a shooting range in rural Missouri by one of our craftsmen who specializes in ballistics. The test results proved to our engineers that the resulting window system could easily pass an official Level 8 test. We then contracted with Architectural Testing in York, Pennsylvania to conduct an independent test on a complete window specimen. The standardized test as conducted by ATI involved shooting the window 13 times in designated locations. Re-View's historically correct ballistic window passed with flying colors.
The Re-View plant manufactured only 11 of these mammoth windows measuring 5 feet wide by over 12 feet tall. Each window weighed in excess of 7,000 pounds. Our engineers and field carpenters had to develop a strategy just to install these behemoths that involved cranes and suction cup lifts. Sometimes our field installers wonder whether our management is insane to engage in such projects.
The Hard Facts About Window Hardware
Apr. 06, 2011
We have found that most specifications for the historic treatment of windows neglect to address the area of hardware restoration in sufficient detail. Most specifications dictate that existing hardware should be cleaned and repaired so it operates properly or replaced in kind if it is missing. 
0% of the locks on preservation projects are a standard sweep lock. The other 20% are specialty designs that may or may not be available to purchase over the counter. Often custom molds must be made for casting these one-of-a-kind elements. We see many historic projects that call for converting the sash to insulated glass or replacing the sash with a replica with insulated glass. These projects also call for restoring the locking hardware and applying it to the sash. Unfortunately, you cannot use the old lock on a sash with insulated glass because the thicker glass occupies the space where the old lock strike resided. You have to purchase a new replica lock with a narrow strike mount that is designed to fit the narrow channel.
On most projects we see in the field, the pulleys have just been painted over and are completely neglected as part of the restoration process. We recommend removing the pulleys for restoration. All finishes should be removed and a new plating applied or a custom cover installed that has the desired finish. The wheel should also be lubricated to avoid squeaking during operation. Some projects call for replacing the ropes with chains because they are more durable and ascetically appealing. Remember that a rope pulley is distinct from a chain pulley so any change in material could involve a change in the pulley.
Let There Be Light
Feb. 15, 2011
Re-View recently had a "Green" experience that could help many companies of all types.
We were founded 18 years ago on the basic principle of resisting the status quo, and are constantly searching for ways to advance our organization. Our plant manager had been reading several studies about how proper lighting can improve the quality of work and increase productivity. Given this information, he commissioned a study on how to effectively improve the lighting in our window plant. He was motivated to use efficient changes in lighting to improve the throughput in the plant. He was also convinced that increases in lighting in certain areas would reduce defects and rework.
What our plant manager didn't realize was how changes in light fixture and bulb technology could dramatically impact the electrical consumption of our plant. We brought in a lighting consultant who evaluated the current fixtures and the illumination throughout the facility. Our management then established target foot-candle ratings for the different areas of the plant, increasing the levels in areas where precision work was performed.
Like many production facilities constructed in the late 1960's, our plant has a combination of sodium vapor high bays and T12 fluorescent drop lights used to illuminate working areas. The lighting consultant quickly identified how we could achieve a three-year payback by replacing our existing system with six-lamp T5 fixtures. The team took a CAD drawing of our plant layout and established a lighting plan that would achieve 30 foot-candles in general areas and 50+ fc in areas where product detail is critical.
We recently tested the installation and discovered that in the assembly and fabrication areas of the plant where we used to have 15-20 fc, we now average 58-60 fc, and all shadows are eliminated. The aisles had 7 fc before the change and now are averaging 30 fc. Our plant employees are now asking for sunglasses and sunscreen.
The team at Re-View is always looking for ways to improve product quality and to reduce costs. We have invested in automated CNC fabrication equipment, computer-controlled saws, computerized glazing, and automated finishing systems. We came across many reports documenting improvements in productivity that were directly associated with changes in lighting. Since our windows are furniture-level quality, we were confident that advances in lighting would enable our craftsmen to perform better work. We also read reports about official improvements in employee satisfaction and safety due to upgrades in lighting. More information on the benefits of lighting can be found on this link: http://www.lightcorp.com/PDFs/industrial/learn/ImpactProductivity_DD1A8.pdf
What our team didn't realize was how advancements in lighting fixtures could also significantly reduce our electricity costs. We are going to recognize a payback on the investment in fixtures and the labor to install within the first three years. That is an amazing return especially since we aren't including the other effects of productivity and quality improvements that will certainly be achieved. Our results profoundly prove that Green building practices really do pay.
The Panes of Putty
Feb. 03, 2011
A customer of mine commented the other day that putty glazing windows is a lost art and I would have to agree with him. As is the case with any art form, there are many hidden challenges in the proper usage of glazing compounds. I am going to address the problems to avoid when finishing glazing putty.
Glazing putty is a mix of boiled linseed oil, calcite lime, inorganic fillers and other common elements. The most popular brand is DAP 33, but there are other manufacturers such as Sarco that produce the similar material. It takes a great deal of practice and patience to become proficient at forming the putty in a straight line and tooling crisp corners. You can find several articles and YouTube videos that might help in accelerating your learning curve. A link to the DAP product data might also be helpful: http://www.dap.com/docs/tech/00010401.pdf
Most people have no concept of how long it takes for glazing compound to cure. Inexperienced users are astounded to discover that it can take up to three weeks to cure depending upon temperature, humidity, and thickness of the application. We have been able to reduce the curing time by introducing heat and fans in a specially designed curing oven. The biggest mistake we have seen in the use of putty is when it is finished prior to proper curing. When this occurs, the paint finish will lose its adhesion and display bubbles, cracks, and wrinkles. It is essential to wait until the glazing has skinned over and attained a firm set prior to applying any finish.
Another problem can occur if the wrong combination of finishes is applied to the glazing compound. Many people want to avoid the priming stage of finishing, which can be catastrophic. A good oil-based primer should be used prior to applying two coats of latex finish paint. Since the putty is linseed oil based and since the compound is flexible and continues to move as it fully cures, the superior adhesion qualities of an oil-based primer is essential. Failure to properly prime the putty can cause your finishes to delaminate.
One should also be careful in using certain finishes over glazing compounds. This especially occurs when putty is used to glaze steel windows. Most finishes designed for metals are not designed with the same elasticity and flexibility of traditional latex-based paints commonly used in wood finishes. The manufacturers of fluoropolymer paints and other steel finishes state that their finishes are not flexible enough to be applied over glazing putty. This type of finish is considered a rigid system and it will crack and eventually delaminate with any movement or thermal expansion or contraction of the glazing material.
Restoration Epoxies
Jan. 12, 2011
The use of restoration epoxies is pretty standard for a wood window restoration project. These two-part systems have become common tools of the trade over the past fifteen years. In the past ten years, several manufacturers have entered the business from mainstream brand names like Minwax to obscure names like Gougean Brothers. One thing is perfectly obvious, restoration epoxies have been a revolutionary development for preservationists.
The manufacturers of restoration epoxy do a decent job of providing directions on the use of their products, and what type of precautions one should take when mixing and applying the material. For example, West System has directions for using their products for various restoration projects. The following link displays many possibilities: http://www.westsystem.com/ss/use-guides/ Abatron has a very useful video on how to mix and apply their products to wood on the following link: http://www.youtube.com/watch?v=2yGQMnmNK1Y&feature=player_embedded
Unfortunately, the manufacturers provide only the basic information on how to safely apply their products and neglect to inform the purchaser on the finer points of product utilization. A great deal of the instructions focus on the CYA that is required when you sell a product that can have hazardous consequences if ingested or used improperly. There are a couple of critical problems that can occur with restoration epoxies that are neglected in the typical instruction manual.
The first problem is the importance of the moisture content of the wood that is being restored. Most restoration craftsmen don't take the time to test the moisture content of the restored wood. Since the wood elements must have their existing finishes removed prior to the application of the epoxy, sills, brickmould, frame members, and sash can often be exposed to the elements after all finishes are removed. They can absorb moisture during this period of exposure. The neutralization of strippers used to remove these finishes can also increase the moisture content of the wood. If the wood has a moisture content in excess of 12%, you can have future problems with the adhesion of the epoxy fillers. The last thing you need is to have
epoxy fillers cracking and buckling. We find that it is important to measure the moisture content of the wood substrate prior to application of the restoration epoxies. There are several moisture meters on the market that are excellent tools for this measurement. We advocate the use of a meter that facilitates moisture measurements below the surface of the substrate. You can have acceptable readings on the surface while the heart of the section of wood is reading 25% moisture content. We use moisture meters manufactured by Lignomat that have two tines that penetrate deeply into the wood. You can find more information on this product by following this link: http://www.lignomat.com/MoistureMeter/index.html
Another challenge we have found with restoration epoxies is the tendency to over apply the epoxy fillers to a wood member. You see this occur particularly on sill reconstruction on a wood window. Many sills that have been neglected for the past 50 years have lost much of their original profiles. If you use the restoration epoxy to completely rebuild the sill to the point where all exterior surfaces are encapsulated in 1/4" or more of the epoxy filler, you run the risk that you will encapsulate the entire wood substrate. Wood must be allowed to breathe. If it doesn't have adequate means to adjust its moisture content, it will either rot or cause the epoxy filler to lose its bond.
If used properly restoration epoxies are an economical and durable way to breathe new life into a historic wood window.
Don’t Get Nailed by the Wrong Fastener
Dec. 23, 2010
Metal fasteners are a common element to most historic windows; often applied to wood stops, stile and rail joints, and trim. Since the most common installation involves setting the nail and covering it with a wood or epoxy filler, most people don’t pay much attention to the quality of their fasteners. There is often a significant difference in the cost of a stainless steel nail and a conventional steel one, tempting many manufacturers and contractors to take the less expensive alternative. This can prove to be a major mistake in the long run.
When a fastener begins to corrode in a historic window, it will cause the finish and any applied fillers to fail. That accelerates the fastener corrosion and opens the window system up for wood rot. We have seen many installations across the country where the entire window system has deteriorated just due to the use of corrosive fasteners. The attached picture features what can happen after only five years to a window stop with a corroded fastener. In this case the corroded fastener initiated a chain reaction of failures, causing the entire lower rail of the window to rot.
Most people know you should use fasteners specifically designed for exterior applications. The most common of these are zinc plated and galvanized. Galvanized coatings are most often thicker than zinc so they have a more durable coating. Galvanized nails are available in several different types and grades of quality, depending upon the thickness of the coating and the coating process. You can get mechanically plated, hot galvanized, electroplated, and hot dipped. All of these have a zinc coating which is applied to a standard steel nail.
Unfortunately, we have had problems with using galvanized nails for the fabrication and installation of historic windows. During the process of setting the nail, the galvanized coating is compromised due to the force required to drive the nail and the friction with the substrate. The galvanized coating can also react with many of the wood preservatives commonly used. Since wood preservative is typically used on soft woods like pine or fir, this will cause premature corrosion of the fasteners. It is also believed that the acids and chemicals inherent in cedar and redwood can cause corrosion of the coatings on galvanized nails.
We recommend the exclusive use of stainless steel fasteners for any fastener that could be exposed to moisture over the life of the window system. Since it cannot be assumed that the owner of the window will properly maintain the window, it makes sense that all fasteners should be stainless. It is important to note that there are varying degrees of quality in stainless fasteners. Type 304 stainless steel nails contain 18 percent chromium and 8 percent nickel. These nails are highly resistant to corrosion in most environments, but will corrode in more intense conditions such as marine climates. Type 316 stainless contains molybdenum which makes it resistant to salt spray found in ocean climates. We recommend type 316 stainless steel fasteners. Upfront they are more expensive, but over the long term they are an excellent investment.
Challenges with Wood Window Restoration
Dec. 03, 2010
It is very exciting to see the window industry begin to embrace the value of restoring historic wood windows rather than resort to replacement. This trend towards restoration is probably driven by the limited lifespan of replacement windows and the recognition that a 75+ year-old window system can be adapted to perform at the same energy efficiency levels as replacements.
Although wood window restoration isn’t rocket science, there are many factors that can undermine the success of your project. Re-View restores thousands of wood windows per year so we have confronted many of the common pitfalls of window restoration over the past 20 years. In this blog, I am going to address the challenges of using chemical strippers to remove paint finishes.
Use of Strippers
Re-View has found chemical strippers to be very effective at the removal of multiple layers of finishes on window components. We utilize dip tanks that contain close to 50 gallons of stripping chemicals since this is the most cost effective means to remove finishes on a large number of window units. Many preservationists are critical of chemical strippers because they claim they ruin the wood. Strippers don’t ruin wood. The improper neutralization of stripping compounds from the window is what ruins the subsequent application of finishes.
It is critically important to effectively neutralize all components that are exposed to strippers. If you use the dip tank method for removal of finishes on sash, it is very important to completely disassemble the sash stiles, rails, and muntins to neutralize the window components. We find that the restoration of the mortise and tenon joints is better facilitated by separating the parts as well. Re-View will test the pH levels of the window components to confirm that proper neutralization has been performed. You want to use pH paper to make sure the wood has reached a level of at least pH7. We often will have to perform multiple neutralization applications if caustic strippers are used since they often absorbed beneath the wood surface.
There are many strippers out on the market and they fall into three different categories: caustic, solvent, and biochemical. The neutralizing techniques you will use will depend upon what type of stripper you are using. Most caustic strippers can be neutralized with a solution of vinegar and water. Some caustic strippers such as Peel Away require a proprietary neutralizer. Solvent strippers can be neutralized with mineral spirits. Many biochemical strippers can be neutralized with water. I fully recommend that you read the directions supplied by the stripper manufacturer. Unfortunately you will have to wade through many pages of health precautions to find the neutralization techniques.
If you are working on windows that were finished prior to 1978, you might have to contend with abatement issues. Proper removal and disposal of lead-based paint is critical. Many people fail to recognize that a fully stripped window that once contained lead-based paint will still be impregnated with lead. If you sand the surface of the wood, you will release lead from the wood fibers. Re-View uses specially designed downdraft sanding tables and all Federal, State, and OSHA approved safety equipment for the sanders. Also beware of asbestos fibers in glazing compound. We find that 25% of our projects have asbestos in the glazing.
Untitled
Aug. 19, 2009
Before I begin to publish posts to the Window Review blog, let me provide you with a little background about my company so you have a better idea of the origin of the posts in this blog. Since the management of Re-View has performed virtually all types of window work over the past 20 years, we are uniquely qualified to provide an unbiased opinion on a number of window issues. It is my intention to provide information based upon facts, not an emotionally-laced hidden agenda.
The management of Re-View became involved in the window business over 20 years ago as Pella window distributors. Over the first ten years, we were involved in replacing and installing all types of windows from major window manufacturers. We have worked with wood window manufacturers such as Andersen, Pella, Marvin, Kolbe & Kolbe, Weather Shield, Eagle, and Jeld-Wen. We have also installed thousands of aluminum window systems from a host of manufacturers. Although we are not proud of it, we have also installed thousands of vinyl windows in commercial structures. This varied background has provided us with an understanding of the strengths and weaknesses of each of these types of window products.
In the 1990’s we began to purchase historically correct wood windows from small regional manufacturers who could fabricate virtually anything in wood. We also became experienced in restoring historic wood and steel windows. As the company grew beyond the Midwestern United States, we discovered that we couldn’t rely on the small output and varying quality of small regional custom manufacturers so Re-View began to manufacture its own windows.
Over the past five years, we have invested in computer automated equipment to improve quality, reduce cost, and increase output. Our state of the art manufacturing plant has become one of the largest producers of custom wood window replicas. We have also established a production mentality to the restoration of historic wood and steel windows. Our union craftsmen travel all over the United States to perform installations and restorations, enabling Re-View to offer a turnkey service for all aspects of historic fenestration.
This complete background in wood, aluminum, and vinyl window replacements combined with our custom manufacturing and restoration expertise, in addition to our field labor capabilities, makes the Re-View team uniquely qualified to provide unbiased commentary on any number of issues relating to historic windows.
Historic Window Blog
Aug. 18, 2009
How one copes with historic windows on a landmark property can be a very complex issue. There is an inherent responsibility or burden depending upon how you look at it that is attached to a historically significant building. Our company has engaged with owners, architects, and contractors from across the country to perform window work on prominent structures, and there are usually more questions than answers as decisions are made to address the problems with historic fenestration.
I intend to write this blog in order to address the many factors one might consider when evaluating how to solve window issues on a landmark property. Many factors come into play when one develops a strategy including but not limited to the following:
• The architectural significance of the building
• The prominence of the existing windows in the architectural style
• The presence of codes or historic guidelines established by State or Federal preservation agencies
• The budget available to perform the work
• The planned use of the building
• Energy requirements of the building
• Security requirements of the building
• The experience of the architect
• The mood of the preservation officer
In addition to confronting the debate as to what should be done on historic windows, I intend to share experiences of our company on window issues. We will look at what works and what fails when working on historic windows.
By posting this blog, I hope to enlighten people on many of the issues that impact a preservation project so that better decisions may be made prior to construction.
