# Rot on trim/underside of bay window



## esk (Jul 13, 2011)

Hello everyone,

We purchased our home six months ago and I'm making things up as I go along, so forgive the potentially stupid questions.

We have a bay window in our living room, and I have notice this past week some rot on the trim (which will be easy to replace I believe, I'm intending to use Azek trim) and also on the bottom "cover" for the window, against the two supports.

The window has a Southern exposure.  Eaves overhang it and I see no evidence that water is dripping from anywhere; i.e. I believe this is just a byproduct of general exposure.

See the two photos below for illustration:

https://picasaweb.google.com/erik.klepper/House?authkey=Gv1sRgCNn6qoK67aS1lAE#5628812299593225426

https://picasaweb.google.com/erik.klepper/House?authkey=Gv1sRgCNn6qoK67aS1lAE#5628812296760175538

Here are my assumptions, not really in order.

1.  I cut some temporary supports from 2x4s to hold up the window.
2. I remove the two supports that are there now.
3. I cut a piece (or can it be pieces? currently there are two pieces there now, roughly 1/3 and 2/3s of the total 140" length) to fit the cavity
4. I install the piece and replace the supports
5. I replace the trim
6. I seal all the cracks with silicone caulk.
7. Everything is miraculously improved.

So my questions:

1. Does anyone see a problem with using Azek for the trim?
2. I intend to use exterior grade plywood to cover the cavity - any recommendations for primer to seal it (I've used Zinnser for other applications in the past; I'm assuming this is appropriate)
3. Recommendations for paint over the primer?
4. Am I deluding myself to think that one piece of plywood to cover the cavity is doable (it's 12 feet total length)? Am I causing serious problems by using the same technique already employed (i.e. one four foot section, one eight foot)?

I'm obviously assuming there's nothing worse going on in the cavity and as best I can tell there are no structural issues.  Does anyone recommend anything exploratory before diving in? If so, would you have an idea as to how I can explore and if I find something really bad, how best to temporarily patch it up before I call in the cavalry?

If you think I'm crazy to try this (I probably am) I'm happy to hear it.  If you think I shouldn't do it myself, any idea how much this work would cost?

Thanks very much for any help you can give.

Regards,
Erik

PS - I'm cross-posting to other forums so I can get as many perspectives as possible.


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## nealtw (Jul 13, 2011)

I would use a recip. saw and remove the plywood leaving the supports in place at least until you see what is happening inside. I would replace the plywood with vented soffit as you should have outside air below the insulation in the cavity. Without airflow this area has trouble drying out when water gets inside. You may find more damage when you get inside.


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## esk (Jul 13, 2011)

nealtw said:


> I would use a recip. saw and remove the plywood leaving the supports in place at least until you see what is happening inside. I would replace the plywood with vented soffit as you should have outside air below the insulation in the cavity. Without airflow this area has trouble drying out when water gets inside. You may find more damage when you get inside.



Thanks Neal!


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## oldognewtrick (Jul 13, 2011)

Eric, I don't think you're crazy for doing the work yourself if you have some carpentry skills, have a basic understanding of how water flows and are not afraid to go forward with this project. After all we are a DIY site dedicated to the DIY homeowner.

Now before you start tearing out structure, I'd suggest building up supports from underneath and stabilizing the window area. Next I'd suggest finding out what the source of the leak is. Windows units should sit in a "pan" type flashing to divert water from entering the substructure. If you just replace what has been damaged, what other failures will occur after the trim is replaced. You never "Tuck your raincoat into your pants" "water always flows downhill" "water will always seek its own level"

We'd like to see you do it right the first time so you/or someone else doesn't have to do it over in the future. Start the exploratory surgery and be sure to post pics, they really help.

OH, and welcome to House Repair Talk!


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