Replace part of a siding panel?

It is not structural in that it is holding up the wall. I'd try to make a "ship lap" joint if possible. You'd have to cut with the saw set to an angle. That way you'd have less change of water leaking in even if caulked.

Hi, I'd think firt thing to check is how come it became squishy? May be water seepage or moisture build up underneath? Is it real plywood or OSB?

It sounds like you've got T-111. It's just cheap fir plywood with grooves cut in it. You certainly can piece in a section, but that would look pretty tacky and might eventually let water in. Also, how are you going to get a good cut on the piece that stays on the house, especially cross-grain?

A new sheet is not expensive and the job is not very involved. If it were me I'd just replace the whole thing. Otherwise you might spend more time and money in the long run trying to "patch your patch".

I've just measured it and found that it's 9ft long -- but the only panels I can find at the local stores are only 8ft; nothing even close at Lowe's or HD, only 8ft at Menards (Wisconsin-based chain).

Perce

| I've just measured it and found that it's 9ft long -- but the only | panels I can find at the local stores are only 8ft; nothing even close | at Lowe's or HD, only 8ft at Menards (Wisconsin-based chain). | Interesting. It sounds like something custom. If you have to use 2 pieces then Ed's advice makes sense to me, but that still probably requires taking it off so that you can get a neat cut.

IO would say it is essential to replace the whole panel and to seal around the window where the water is getting in to make the lower part "squishy". Do it right or wish you had. "why is there ALWAYS enough time and money to do a job over (and over) but never enough to do it right??"

What made it soft in the first place? Likely water. Where did the water get in? Likey at the window. How do you stop water from getting in? Fix the leak How do you fix the leak? Remove the window trim - Likely. Remove the trim. Remove the whole panel. Determine where it was leaking. Fix the leak and replace the entire panel

DONE.

The other question - what's he going to do with the rest of the panel he has to buy????

Don't "wuss out" Fix it.

Go to a real lumber yard. The 9 ft long pieces are available. The box stores don't usually carry that size and the quality of their T-111 is not that good. Often it will be OSB and not plywood. You get what you pay for.

No, it is not custom. They are available at a good lumber yard but probably close to never at a big box store. The ones at the big box stores are quite often OSB instead of plywood.

The "squishy" part is several feet below the window opening -- and not directly below.

Perce

I haven't set eyes on the ones at Menards, but the online description says 5/8" thick *plywood*.

Perce

Go to a REAL builder supply. 9 foot and longer have always been commonly available in siding - not as easily available in regular plywood.

Oh, and I discovered the "squishy" part when I noticed some orange stuff (fungus?) on one edge (the edge farthest from the window) and started scraping it off.

Perce

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There's a leak somewhere and I agree it needs to be addressed as to where the water came from--that the collection isn't directly below the window itself doesn't _necessarily_ mean it isn't a flashing problem there running along an internal cross-brace to that point where it (the brace) meets the stud and forms a collection pocket, say. Simply covering up whatever the problem again isn't going to make that go away and you don't know what structural damage has been created internally that only shows up as the siding externally...

A ship-lap joint us not typically cut at an angle. I'm not saying that an angled cut is not desirable, but any type of angled cut would not be your typical ship-lap.

Could you explain how a ship lap joint with an angle would be cut? I'm always willing to learn something new.