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joew623
Attic Insulation Advise Needed

Im working on an attic insulation project at my home. The roofers used way too long of nails when they roofed the home last and the nails are everywhere sticking out about an inch. Before I insulate, I wanted to install the plastic air vents between the trusses to allow for air flow from the soffet vents. This was impossible do to the huge number of nails poking through. My trusses are spaced 24 inches. I decided to install 24 inch wide by 48 inches tall pieces of hardboard attaching to the truss. It took me 3 days and I installed them all. It looked great and gives much more air flow than the typical between the truss plastic chutes. 2 years later I crawled in the attic and the hardboard has "sagged" about and inch in the center over time. the hardboard is still hard, but just sagging. Each piece of Hardboard is attached with 4 short drywall screws.

My question for you is:
Should I install some perpendicular 1X3 strips to keep the hardboard from sagging further? will it sag even more over time if left alone? Will hardboard eventually decinigrate and deteriorate? How long do you think it would last? Should I add more screws/nails? Any other ideas for my situation?

Please see attached images.

Debra
Re: Attic Insulation Advise Needed

yeah, I think strips would have been a good idea. I don't know how to change what you have though. Invest in a hard hat while you're working under all those nails.

canuk
Re: Attic Insulation Advise Needed

joew623 ... good for you ... well done.:)

I'm thinking those panels you installed are around 1/4 inch thick ... so most of the sagging is from good old cousin gravity and a little help from his sister humidity.

This is more of a cosmetic issue and it will continue doing what it was intended to do ... allow the air stream from the soffit vents.

They're not directly in the elements they should be okay for some time I would think.

Btw .... nice neat job with the cables.;)

havanagranite
Re: Attic Insulation Advise Needed

I agree with canuk, and also would add your nails sticking through is typical, a shorter nail if it didn't stick all the way through would pull back and you would find your shingles laying in the yard.

JLMCDANIEL
Re: Attic Insulation Advise Needed

Ditto to above posts.
Jack

joew623
Re: Attic Insulation Advise Needed

Thanks for the input! Do you think I should add some sort of wood strips under those going across the attic to aid in support for the hardboard panels? Or do you think it will last long enough as is?

Also, If it is typical for nails to be poking through, how does one install those plastic shoots against the plywood decking?

canuk
Re: Attic Insulation Advise Needed

Ya know .... I was looking at the photos again and it looks as though the top wall plates wouldn't be covered with insulation.... similar to what's shown in the above diagram.... ignoring the knee wall reference.

If the homemade baffles were in between the rafters say about 1 1/2 inches from the underside of the sheathing this will allow enough room to extend the insulation over these top plates and still provide adequate channel for the air stream..

So if you take a 2x4 and rip it in half ( roughly 2 2x2's) place them inside the rafter bay against the sheathing and screw them to the rafters .... attach the hardboard panels to the underside of the 2x2's.

Otherwise .... if you feel the insulation is fine then leave things as is.

If the cosmetics of the panels sagging bothers you then sure secure lengths of 2x2's across the edges for support.

Quote:

Also, If it is typical for nails to be poking through, how does one install those plastic shoots against the plywood decking?

Carefully.;)

Hope this helps.:)

Debra
Re: Attic Insulation Advise Needed
canuk wrote:

So if you take a 2x4 and rip it in half ( roughly 2 2x2's) place them inside the rafter bay against the sheathing and screw them to the rafters .... attach the hardboard panels to the underside of the 2x2's.

Otherwise .... if you feel the insulation is fine then leave things as is.

If the cosmetics of the panels sagging bothers you then sure secure lengths of 2x2's across the edges for support.

Carefully.;)

Hope this helps.:)

There you go, I knew there was a way but I couldn't think of it last night.

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