Great Stuff to fill in gaps on exterior trim?


Old 11-18-16, 06:53 AM
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Great Stuff to fill in gaps on exterior trim?

i wanted to get your advice on some trim i am trying to place on the side of my house after having replaced some t111 boards. i attached a couple of pictures to help you see what im talking about. i cannot get the trim pieces to line up perfectly, there are areas where the trim lines up well and then spots where there is about 1/4 to 1/2 inch gap. so i wanted to know, could i fill the gap with great stuff, and then sand the great stuff down and paint over it? or should i fill most of the gap with the great stuff and then top it off with a silicone caulk and then paint over that? i think i will need to remove the gutter to get at everything correctly.

i have basic equipment like a jig saw, miter saw, drill but no table saw or circular saw.

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Last edited by PJmax; 11-18-16 at 09:15 AM. Reason: reoriented pictures
Old 11-18-16, 06:57 AM
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How wide is the gap? I'd want to slip a piece of wood in there and then caulk it with a paintable caulk. Is the gap tapered? If need be I'd try and find some one to cut the filler strip.
Old 11-18-16, 07:09 AM
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Contrary to what marketing would have you believe, expanding foam is NOT a product for exterior use. Unless you love your house to have orange poop all over it, then go right ahead.

Your trim needs to be nailed together. Possibly it should be removed and reinstalled to do it correctly. Then you will have small joints that can be caulked. Don't caulk a joint that can be nailed together first. Nail it first, then caulk it.

If you have a bulge behind the siding, you probably missed pulling a few nails that were sticking out.
Old 11-18-16, 07:29 AM
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hi. the gap ranges between 0 and 1/2 inch depending on what section of the trim you are dealing with. i am hesitant to remove the trim piece that has been in place for years and seems to be holding up well. do you think i could bang the t-111 board with a hammer and push it in enough to get a better fit for the trim?
Old 11-18-16, 07:40 AM
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Expanding foam isn't rated for exposure to UV light, either.
Old 11-18-16, 07:46 AM
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You could fill the gaps with epoxy wood filler, like WoodEpox, and then paint, although the long term results won't be as good as redoing the trim. You could improve the chances for the filler by driving a few stainless steel brads so they stick into the gaps and give the filler something other than the wood to hold on to. I think this would give better results than painted foam, but it's still kind of a hack.
Old 11-18-16, 04:48 PM
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Possibly it should be removed and reinstalled

Ho possibility about it, the trim should be pulled off and reinstalled tight!
Old 11-18-16, 07:42 PM
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If the downspout will be reattached in the same location, just extend the trim board another 3 1/2" using a 1x4 for the full length.

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