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what product to use behind vinyl siding


bing1's Avatar
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12-21-16, 12:05 PM   #1  
what product to use behind vinyl siding

Hi,

We recently purchased a home that was built in the late 1970s. it appears that the "material" sitting right behind the vinyl siding is damaged from sloppy work. way bigger holes than what's needed for AC power, hvac exhaust and intake ducts not sealed. how should I go about fixing this for the long term. I can feel cold air streaming through these vulnerable spots.

The "material" seems to be some type of compressed fibers. On the external wall, i see fiberglass insulation, dark black "material" and then vinyl siding.


1. should i just spray foam the holes and then put new fiberglass insulation and staple it to the studs?

2. leave the "material", add maybe a radiant barrier or something similar, and then put new fiberglass insulation and staple it to the studs? would the radiant barrier cause any moisture issues if it was sandwiched between the fiberglass insulation and "material"?

3. better recommended option?

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12-21-16, 12:18 PM   #2  
Material looks like asphalt fiber board.

My opinion, some sheet metalon the outside trimmed nice and neat, screwed into the studs.

Use a good exterior cauld, like Quad, to seal, replace the insulation and your good.

Spray foam is not a good material for sealing large holes, it will break down with time.

 
bing1's Avatar
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12-22-16, 12:14 PM   #3  
Thanks Marq. Can the sheet metal option be done from the inside. In order to do it from the outside, i'll have to remove the vinyl siding, which I don't know how and wouldn't want to either. Thanks.

 
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12-22-16, 01:08 PM   #4  
Sorry bing but I'm a little lost.
All of that insulation needs some work and it needs to be covered by a rigid air barrier, like drywall. Leaving the kraft paper exposed, even IF stapled neatly in place still allows warm humid air to leak past and form condensation.

Before I suggest starting over, tell me why this room is unfinished? It looks like it has been this way since the 70's, except for the newer high efficiency exhaust.

Bud

 
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12-22-16, 01:32 PM   #5  
The home is a split level and the said "utility" room is on grade. It houses the HVAC, washer/dryer, and water heater. I'm not sure why the previous owners didn't finish the room with drywall. As of now, i think it would be somewhat difficult to put drywall up. All the PVC piping and copper plumbing sits pretty flush to the studs and fiberglass batting.

As you can see in the picture (barely), there are holes penetrating the black fiberboard. A lot of cold air is flowing through the siding, through the fiberboard holes and into the house. I put my fingers through the hole and didn't feel any vapor barrier (wrap) between the fiberboard and vinyl siding.

I'm definitely going to put new fiberglass batting in, but just wasn't sure what's the best approach to patch the hole on the fiberboard.

Any suggestions is greatly appreciated. In addition to sealing air leaks, i want to make sure i don't inadvertently cause a moisture issue around the problem.

Thanks Bud

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12-22-16, 02:11 PM   #6  
For a home today it would be a layer of house wrap under the vinyl siding. You wouldn't want a vapor barrier there as it would create a condensation (cold) surface. I have never had to deal with that compressed fiber material but have seen it mentioned many times in the posts. Basically a low cost substitute for plywood sheathing.

I agree that the current situation will be difficult to improve, but it needs to be on your list. Even if you just redid most of the insulation and then slid in a layer of plastic. It would be a vapor barrier, which isn't really needed in your climate zone, but more importantly it would be an air barrier.

The current insulation looks to be tucked to the inside surface of the studs. A better installation would be face stapled, it leaves fewer wrinkles and gaps. Even better would be Roxul (a mineral wool) which has no facing, just friction fit, and then covered with the plastic air barrier. But the fiberglass will work.

As for the holes I like something rigid secured in place and sealed with caulking. Can foam will work but as Marq said, it isn't really for large gaps/holes.

Bud

 
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12-23-16, 08:36 AM   #7  
Bud,

What do you recommend I use to seal the holes? would a piece of foam board work with caulking around it? Would moisture/mold be an issue between the foam board and fiberboard even if it's sandwiched together? Whatever I do, i will also apply the solution to the area where the hvac exhaust/intake is located above the wall. Thanks and happy holidays.

 
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12-23-16, 08:49 AM   #8  
Some rigid foam board will be fine to patch small areas as you stated. If you were to fill an entire wall area then there are thickness and thermal barrier concerns.

Bud

 
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