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OandLE
Repairing deteriorated window sills

I have several wooden window sills that are partially deteriorated and would like to use an epoxy to repair them. I read in "This Old House" of a material Tom Silva uses but can not find that issue. Can someone supply the name of the product and where can purchase it? Thanks!
Bob

JLMCDANIEL
Re: Repairing deteriorated window sills

Here's two of the epoxy products that has been used on the show
https://www.ndic.com/systemthree/endrot_kit_order.asp
and
http://www.advancedrepair.com/pricing.htm

Jack

A. Spruce
Re: Repairing deteriorated window sills

I just saw a post by Goldhiller, in an unrelated thread, that epoxies don't expand/contract with the wood. If this is the case, then replacement would be the better option. I personally have never used epoxies, so I don't know their limitations.

havanagranite
Re: Repairing deteriorated window sills

I have used ones similar to what jack linked to on some exterior column repairs and have had no problems.

JLMCDANIEL
Re: Repairing deteriorated window sills

Sprucey, you should check out the one called flexable epoxy it works a lot better than staples and caulking.:D
Jack

havanagranite
Re: Repairing deteriorated window sills
JLMCDANIEL wrote:

Sprucey, you should check out the one called flexable epoxy it works a lot better than staples and caulking.:D
Jack

yea but you could improve it by adding staples and they would help keep it from cracking, and the caulk would seal it all together as one unit.:D

JLMCDANIEL
Re: Repairing deteriorated window sills
havanagranite wrote:

yea but you could improve it by adding staples and they would help keep it from cracking, and the caulk would seal it all together as one unit.:D

I guess we shouldn't confuse the OP, he may not have read that thread.
Jack

goldhiller
Re: Repairing deteriorated window sills

QUOTE=A. Spruce;29289]I just saw a post by Goldhiller, in an unrelated thread, that epoxies don't expand/contract with the wood. If this is the case, then replacement would be the better option. I personally have never used epoxies, so I don't know their limitations.[/QUOTE]

Well....IME, both epoxies and polyester resins fillers (such as Bondo) can be used successfully long-term ...under the right circumstances or with "proper" techniques. As a matter of fact, epoxies make great fillers for wood in interior applications where the wood isn't subjected to the same moisture differentials as exterior wood is. It's in exterior applications that problems can readily arise.

Windowsills would be a prime example of a difficult exterior situation. Using epoxy or polyester resin to replace say, broken off pieces of rake molding which is under roof works really well...usually...without going thru any "extra efforts".

What we see on TV when these types of products are used for windowsills (or whatever) is a really nice looking repair. They all look great on day-one. But check back in 2, 3 or 5 years.

Let's say that the filler was used to replace a rotted out pocket of wood in the center area of a windowsill. The patch is surrounded by a "frame" of wood. When that surrounding wood gets wetter/damper, it expands. The filler doesn't give or move along with it. The wood expands against the sides of the solid patch and compression set takes place. Much the same phenomenon as a wooden hammer handle getting wet and compression setting aganst the metal surrounding the hole in the handle. When the wood handle dries out again, it's now loose in the head...because there is a crack between the wood handle and the hole in the head. In the case of the filler patch, a small crack will develop around the filled area. This is where water will enter...sooner or later. BTDT.

However, I have had long-term success using these types of fillers for this type of exterior fill. I hog out the rotted material until reasonably sound wood is found. Then I place something to serve as mechanical anchors for the fill material. Usually, a couple/few screws such that their heads are below final grade. Then I fill the pocket with the filler. As the filler sets up, there will be a point (3-10 minutes depending upon ambient temps, etc) when it becomes firm-ish, but can still be easily carved with a sharp utility knife blade or similar. I quickly & carefully, carve out a perimeter crack in the filler about 1/16" to 1/8" wide. Then I wait until the filler is totally set/hardened. Time to sand the filler flush to the surface. Then I blow the wood dust out of the crack and fill it with a flexible polyurethane caulk. When ready, I prime and paint. The repair looks great and the poly caulk "gasket" absorbs the expansion and contraction of the surrounding wood. I've put patches like this in windowsills over 15 years ago that are still in great shape today. Prior to using this technique, the patches eventually developed perimeter cracks and let water in again.

The reason I didn't suggest this for Walt's deck is because he isn't dealing with a painted surface where all the filler and caulk can be hidden. (But long ago in his thread....I did suggest that he use clear epoxy to fill in/level out irregularties in his interior flooring because I know that will work fine there. Less concerns about the expansion and contraction deal because it's inside. No poly "gasket" around the patch needed, either. Done that many times in 30 years, including here......and they're all performing just dandy.

Disclaimer - Your mileage may vary. :D

A. Spruce
Re: Repairing deteriorated window sills
havanagranite wrote:

yea but you could improve it by adding staples and they would help keep it from cracking, and the caulk would seal it all together as one unit.:D

Are you talking about stapling the epoxy to the wood then caulking or adding the staples to the caulk, because if you do the latter you can install and finish in one coat. Mix a little paint in with it and you'll be done so fast you'll home having a beer before you left.:D

JLMCDANIEL wrote:

I guess we shouldn't confuse the OP, he may not have read that thread.
Jack

True, there's no need to harm the innocent. :p OandLE, we're just having a little fun, we now return you to your regularly scheduled topic.

goldhiller wrote:

Disclaimer - Your mileage may vary. :D

Told ya Goldie would know ... :D

BigWalt
Re: Repairing deteriorated window sills
A. Spruce wrote:

Are you talking about stapling the epoxy to the wood then caulking or adding the staples to the caulk, because if you do the latter you can install and finish in one coat. Mix a little paint in with it and you'll be done so fast you'll home having a beer before you left.:D

True, there's no need to harm the innocent. :p OandLE, we're just having a little fun, we now return you to your regularly scheduled topic.

Told ya Goldie would know ... :D

Oh man...you guys are too much.
I'm laughing so hard....:D

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