Anyone replace an outside window sill that is rotted?? What type wood is best for this?? Any special do's and don'ts??
[OP]
Member
Anyone replace an outside window sill that is rotted?? What type wood is best for this?? Any special do's and don'ts??
John T.
Contributor
Yup. I have in my house.
I used Fir, but it's possible in your area southern Yellow Pine might be good.
I made sure I primed all the way around before fitting it.
Young enough to remember doing it;
Old enough to wish I could do it again.
Contributor
Most of the ones around here are fir or hem - fir ( hemlock") . Real fir is much better than hemlock. Many times the sills have been run bark side down. They should be bark side up to avoid the razor blade like grain. The solvent base copper naphthalate will definately add many
years of rot free use. I had a couple sills that had been run the wrong way . I patched them with Bondo and then covered
them with canvas and painted . That is a long term easy fix.
Contributor
Redwood is what used to be used in California. My 70 year old ones are in pristine condition touching rotted trim pieces of fir or pine. Of course they are pure heart with no knots which is not sold anymore. The trim I remade in todays redwood and soaked in buckets of the green rot preventer for several days before installing. I used stainless finnish nails to put it all back together.
Bil lD.
I've used treated lumber to replace rotted parts of windows.
Contributor
Depending on the extent of the rot, you might consider patching instead of replacing. Abatron's liquid wood/woodepox combination works well. The first is a low viscosity epoxy that soaks into rotten wood and hardens it up. Then overfill cracks, voids, missing areas with the putty-like woodepox; once that is cured, you can plane/rasp/sand it to shape. Smith's CPES also works well for consolidating punky wood, but it stinks to high heaven.
-- Jim
Use the right tool for the job.
Member
I'll second the recommendation to use the Abatron products, they work really well. One thing I learned from another restoration fellow was that the Wood Epox can and should be applied directly onto the Rot Consolidate (the liquid stuff). In this way the two bond to each other better than if the rot consolidate was left to dry first. And James is not wrong about the smell of the rot consolidate!
If you are faced with replacement of the sill we usually use white oak. Others that would be good include black locust (hard to find), Spanish cedar (on the soft side), or mahogany (expensive).
Believe it or not I really enjoy replacing sills! Even better is when I get to reproduce an old window frame completely.
Originally Posted by James Morgan
Contributor
I usually use White Oak, but prefer Live Oak, when I can get it.
I won't use epoxy on South, or West facing walls any more, and especially not in a SW facing inside corner. It breaks down after a decade, or two, from the heat. Inside a SW facing corner, quicker than that. That might be different in places much North of here, but I have had some break down in those places, whereas on the same buildings, the epoxy is fine on North, or East Walls.
Member
I'd recommend Accoya. Very rot resistant, very stable, and quite easy to work with.
Contributor
I don't mean to hijack the thread, but I'm curious why none of the very experienced folks (way more knowledgeable than me) above mentioned cedar. I don't have much experience with this, but I got really tired of repairing/replacing the painted fir trim boards on my previous house and eventually just ripped it all off and replaced with painted western red cedar. I have since heard something about cedar not working well with white/light colored paint, but that wasn't something that I had any issue with. After the responses that I saw above, I suspect I made a poor choice, though they seem to have lasted.
The fir that I hated was only painted on exposed sides, so I'm sure that was a good portion of the issue -- some of the trim, especially the caps at the top of the windows rotted away to nothing in ~7 years. Sloppy mass-market builder.
--Dan
Member
White oak is a good water resistant wood and has very good strength.
Contributor
Dan, way too often hemlock is being sold as "fir". Good fir is good stuff
Contributor
I think the bit with cedar is the tannin can bleed through light paint. I'm not keen on it because sometimes it doesn't take and hold paint well, and because I had a nasty case of red cedar asthma 25 years ago. I still start wheezing if I work with it, which I normally avoid.
I prefer white pine for exterior trim. It machines well, is friendly to work with, is stable, takes paint great (with an oil based primer) , and has moderate rot resistance. If it is maintained, it will last indefinitely.
Contributor
Cellular PVC like Azek, etc.
Guest
You can buy new sill nosing from Azek.
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