At the start of the summer of 2019, we were fortunate enough to begin work on the exteriors of the windows at Mount Pleasant Mansion in Fairmount Park. It is a beautiful Georgian style home that was built in 1761. At the time it was built it was one of the finest homes in the Philadelphia area. Over 250 years later, it is still quite an impressive home.

The original owner was a pirate; OK well technically he was a privateer, which is really just a government sanctioned pirate. It is a matter of perspective what you call him then I suppose. But if it walks like a duck and quacks like a duck…

About 20 years after it’s construction, the notorious Benedict Arnold purchased the home. It seems he was quite busy turning coats at the time and never found the time or funds to actually move in. His plot was discovered not much more than a year after the purchase of this fine mansion.

Now on to the most important part of this home’s history. In 2019, the world renowned restoration company know as Iconic Windows was hired to restore and preserve the exteriors of the historic windows of the main building. The Philadelphia area was in a frenzy at the news of the Iconic crews’ arrival. Even security had to be brought in. Not surprisingly, the Iconic Windows crew deftly restored the windows back to their original splendor.

This was such a fun project and we were so grateful to be involved. The weather could not have been better for it. We even had a nice surprise high atop one of the Palladian windows. Looks like someone named James etched his name into one of the glass panes. What a fun find! Sorry James but we just blew up your spot.

What I want to talk about today is wood of course.  More specifically I would like to discuss the proper treatment of old wood in prepping for a durable painted finish.

As with all painting tasks, understanding your substrate is the first step in choosing your finishing approach.  You should approach metal different than you do wood.  That seems obvious.  However, even most pros don’t realize that different types of woods also require different approaches.  The “type” of wood that we are most concerned with today is old wood.  As historic restoration contractors, we work primarily with wood that is at least 80 years old.  We have come to realize that old wood must be approached differently than new lumber if you want to have a quality finish.

Before we start talking about what you need to do, let’s delve a bit into wood and how it ages.  Wood is a fantastically resilient material.  It can last essentially forever if a few simple conditions are met.  It must be protected from the sun and it must avoid prolonged periods of moisture saturation.  Most people think that water rots wood.  However, water on its own does not hurt the wood at all.  It is in fact fungus that causes all rot and fungus requires a certain amount of moisture in order to survive.  If the moisture content in the wood is below 20% the majority of the time, with the ability to dry out when it rises above that, then the wood will never rot because the fungus does not have a chance to grow.

Quick tangent:  I always find it funny when we work on windows from the early 1900’s.  Up until that time, standard practice in building windows was to assemble the window parts, drill a hole through the tenons, and insert a wooden peg to hold the joint together.  At the turn of the century, metal fasteners were becoming cheaper and easier to acquire for builders and they started using steel nails instead of wooden pegs.  Now 100 years later, we are finding something interesting.  The metal nails are failing.  They are often completely or at least mostly corroded yet the wood surrounding them is still perfectly sound.  The moisture content in the wood was harmless to the wood but the “mighty” iron crumbled under it, literally.  All of those fantastic homes from the colonial period wouldn’t still be standing if they were held together with steel nails.  Food for thought.

So we know we need to keep the wood from getting wet for prolonged periods but there is another enemy to deal with:  the sun.  The sun, and it’s UV rays in particular, will also damage wood.  The lignin in the wood cells is damaged by UV light in a process called photo-oxidation.  Lignin is what gives the cell walls in wood it’s strength.  As the lignin in the cells degrades, cracks develop in the wood.  These cracks allow surface water a place to get in.  In addition, since the cell walls are compromised they are now more absorbent.  Now the surface of the wood starts absorbing water like it is the end grain.  Moisture content in the wood will begin to rise and the wood is now more amenable to fungus growth.

Clearly, the takeaway is that you want to protect your wood from the UV rays of the sun and high levels of moisture content.  The obvious choice here is paint.  There are a number of clear finishes that can perform well but nothing can compare to paint.  A quality paint job will block almost all UV rays and keep the moisture from getting into the wood.

So the question now isn’t if we should paint the wood but how do we keep the paint from failing.  We can get into the details of a quality paint job in another post where we discuss paint prep, primers, and paints.  Today we will just focus on one particular step that is often required when dealing with old wood that is not required with new wood.  After 100 years, it is safe to assume that the wood was not always perfectly protected from the elements.  It is highly likely that various sections spent some time unprotected or poorly protected from the elements.  Thus, there has probably been at least some UV damage to the wood.  If you do not address this you may run into problems.

As was mentioned earlier, as the lignin in the wood cells is degraded it becomes more absorbent and sponge-like.  This presents a problem when it comes to priming and painting the damaged wood.  New wood will very lightly absorb the primer, which is great for getting good adhesion, but it will mostly sit on the surface to cure.  The UV damaged wood however will try to absorb every last bit of liquid it can until the damaged wood cells are full or the liquid runs out.  The problem is that primers are a delicate mix of solids and liquids.  The liquids are there essentially to help the solids assemble and cure properly.  All paints recommend you to not paint when temperatures are too high or in direct sunlight.  That is because if they dry too quickly the paint or primer will not have enough time to cure properly.  The same thing is happening when you paint the old damaged wood.  The wood will suck up all of the liquids and leave all of the solids on the surface.  It is like trying to use a colander as a soup bowl.

If anyone has ever had a section of wood on their home (usually in a high sun exposure location)that they just cannot keep the paint from peeling on no matter how good they prep it, this is probably what is happening to you.  The biggest problem is that you really can’t tell if wood was damaged or not by looking at it.  Nevertheless there is a simple way to deal with it.  There is a pre-treatment that you must do to the wood prior to priming.  What we use on windows in our shop and we call our “sealer” is really a consolidating oil-resin that we make ourselves.  Historically, painters would use a 50/50 mix of linseed oil and turpentine as their recipe and that still works fine.  Since there are some concerns that recipe may be a bit susceptible to fungus growth, we use a 50/50 mix of mineral spirits and an alkyd oil instead.  The oil we use is usually the product know as Penetrol, which is sold as an oil paint additive and conditioner.  We simply brush this sealer onto the bare wood.  This is when you will find out if the wood was damaged.  If it was damaged you will see the wood absorb the sealer as soon as you brush it.  If it wasn’t damaged you will see it sit on the surface of the wood.  When you encounter sections that are sucking up the sealer, just keep brushing it on until it stops absorbing it (or until you give up).  After you give the sealer a bit of time to dry, you can move to priming and painting as you would any other wood.  It’s that simple.

If you perform this one simple step every time you encounter some old wood that may have been damaged by UV rays you could avoid a lot of aggravation and considerably extend the life of your paint job.  The devil is in the details.  Sadly, this is a detail that even most high class pros aren’t aware of but now you are!

Last fall we started working on a project at Haverford College.  They were planning on renovating and re-purposing their old Ryan Gymnasium.  We were hired to restore all of the existing original windows in the building as well as build a few custom windows to match the original windows exactly. It is now a year later and the project is complete.  We are so glad to have been a part of this project and are very proud of our contribution to the project.  Let’s take a quick look at what was done.

The building was originally built around 1900 as a gymnasium.  On the main floor was the basketball court and main gym floor.  A floor above wrapped around the perimeter of the building was a wood running track.  In the basement at one point, there was a swimming pool.  The pool was at some point filled in and the basement was mostly just locker rooms.  Up until the start of this project, surprisingly few changes were made to the gym.

With newer gym facilities elsewhere on campus, the old gym no longer served a purpose.  So the college decided to convert it to an arts building.  Many changes needed to be made in the process.  Fortunately, the folks at Haverford College understand the value of preservation and they were determined to preserve as much of the historic character of the building as possible.  One part of that was to restore the old windows in the building.  They wanted them to look just like they did when the building first opened.  And that we did!

We removed every window in the building and restored them back at our shop.  All paint and glazing was removed from the windows and all glass was saved and reused.  Most of the windows were large 18 over 18 double hung windows.  There also were some massive 38 over 24 double hung windows.  The upper sash alone was over 8 feet tall!  The windows were a lot of work but they certainly were worth it.  Check out the restored windows on our Portfolio Page

This project also required us to build 7 custom new wood windows to match the existing windows in all respects.  Since the project was a LEED certified project, we were required to use FSC certified lumber for the windows, which left us using poplar.  We built every part of the window sashes and window jambs and casings in our shop in Bryn Mawr.  The window sashes are exact matches of the originals with true through mortise and tenon joints and the exact same muntin profile.  They came out great.  Take a look at a couple photo galleries of the replicated wood windows on our Portfolio Page

This was a really fun project.  It is rare to work on a large construction project and have them value the work that we do as much as they did on this project.  So I would like to express my gratitude to the guys at Whiting-Turner that were managing this project and all of the smart people at Haverford College that had the foresight to know and trust that our services were worth it.  Thank you!

Many of us love the old wavy glass we find in our old windows.  However, we often have a hard time finding old glass to replace the broken panes in our windows.  Often this leads to an all too common act that most of us old house lovers and owners don’t like to admit we do:  dumpster diving.

The first few times you do it, you may have a rush of adrenaline and the thrill of it can be exciting.  Even your righteous self will gladly justify that you are sacrificing for the good of the planet, your home, neighborhood, [insert other token excuse here].  It will even leave you with a strange sense of accomplishment.  Embrace the thrill while it lasts; it is a sort of right of passage really.  There was really no avoiding it.  But one day the glow of adventure may wear off.  That day you may come to realize that you are just a guy in a dumpster.

This post is to remind people that there are often alternatives.  In this case, new glass made to look like the old glass can be purchased.  It is expensive for sure.  But it just may be worth it to not have to climb in a dirty dumpster ever again.

As I browsed through the comments, I was caught a bit off-guard.  The resounding response went something like this:  “Toss ‘em, no guilt.”  Most alluded to the superior energy efficiency of the replacement window, which is common knowledge of course.  Obviously I am aware that this view exists but for some reason I thought it was an ignorance that was slowly but steadily dying.  I figured many had noticed the variety of lawsuits over the years against window manufacturers over false information regarding energy efficiency.  Or perhaps they have heard commercials from large manufacturers trashing vinyl windows and not daring to touch old windows.  Even better, maybe they read the Consumer Reports article from August 2014, which started by saying “Forget what the ads say.  Saving money on your energy bill is not the reason to replace your windows.”  Clearly, the propaganda from the window manufacturers over the years has proven to be far more insidious and stubborn than I had originally thought.

A few days after reading that blog, I sat in on a historic windows seminar conducted by the folks at Traditional Building.  The two speakers were Robert Loversidge, an architect with extensive experience in historic preservation, and Chick McBrien, the Senior Architectural Project Manager at Marvin windows.  It was a generally decent presentation covering what to do with old windows in old buildings.  At the end I asked a question just to see what response I would get.  I asked, “In terms of energy efficiency, how does a restored and weatherstripped original wood window paired with a new wood or aluminum storm window compare to a replacement double-pane wood window?”  The response from Loversidge I will paraphrase but went something like this:  Obviously we have a wealth of data about new window energy specs but we have only in the past 5 years started to receive information regarding old windows.  But based on my experience and the data I have seen, the original window/storm combo if anything might be more efficient because it has a greater mass of air between the two glass panes than a replacement window.  Chick, the representative from the new window industry, who was surprisingly objective throughout the seminar did not argue and remained silent.

Why is the truth so much harder to spread?  There is a dearth of evidence out there refuting the energy efficiency myth but very little seems to be getting through.  I try my best to stay partial when discussing the replace/restore dilemma with people.  I generally feel that if it is their home then they should be able to do what they want with it.  But I will not stand by while people make decisions based on false or misleading information.