# Insulating an attic with loose fill fiberglass with a door hatch



## Windows on Wash (Aug 30, 2011)

How much do you plan on going up inside the attic what you blow in an R60 of insulation?

The attic is going to become far less navigable once you have about 15 inches of loose fill insulation on the floor.

Most times we will build risers on the side of the attic hatch out of either rigid foam or framing lumber.

We then back the attic side of the hatch with 4 inches of Polyiso foam insulation. That gives you all the R-value you will need in the hatch and makes it far easier to handle than having something with fiberglass batts on the back.


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## steppinthrax (Nov 29, 2010)

Windows on Wash said:


> How much do you plan on going up inside the attic what you blow in an R60 of insulation?
> 
> The attic is going to become far less navigable once you have about 15 inches of loose fill insulation on the floor.
> 
> ...


Thanks,

I've been doing a lot of work in the attic, I've installed two bathroom vent fans so far and I've installed a baffle on each and every cavity. I don't imagine going in there often once I blow foam, but I want to do annual inspections to verify leaks/mold etc.... Also at some point I will need to re-shingle.


Can you describe how to build a wood box around the opening. I usually use a small step ladder, hold onto the sides and pull myself up. My concerned is if I build a wall I will need a longer ladder to reach the sides. Also the wall I build likely won't support my weight.

I need something strong!! LOL


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## Windows on Wash (Aug 30, 2011)

If you plan on getting up there on the regular, I would either find a spot to put in a set of attic stairs or enlarge the current opening and do that. 

They also make telescopic pull down stairs.


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## steppinthrax (Nov 29, 2010)

Windows on Wash said:


> If you plan on getting up there on the regular, I would either find a spot to put in a set of attic stairs or enlarge the current opening and do that.
> 
> They also make telescopic pull down stairs.


Yeah,

I think I'm going to have to build a box. I would rather do that than putting in stairs etc...


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## SPS-1 (Oct 21, 2008)

Ditto on what WoW said on risers and walkway. I have a short one in the center of my attic -- wish I would have put up more.

I have about R-70 in my attic (rockwool batts). Near the hatch I have some XPS which is thinner and makes getting up there easier. Actually, one smaller piece of the XPS can readily be removed for climbing up there. Made new hatch out of plywood with XPS on top, and put a closed cell foam gasket to make sure it was air tight. I ended up needing to put handles on the underside of the hatch to pull it down tight.

Don't know how wide-open your access is, but ask yourself the question that if you build an 18" box around the opening, can you still get up there? It might be easier said than done.


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## Bud9051 (Nov 11, 2015)

As an energy auditor I have poked my head up through a few tight attic hatches to find a sea of insulation. That's as far as I go, as trying to shuffle around through that foot plus of insulation will do more harm than good. My last building, 50x80 full truss roof, I knew I would be going in and out of that attic often, so I built a 4' wide raised walk right down the center. It served its purpose well.

The cofferdam is necessary to keep the insulation in the attic, but the walkway (as others have suggested) a must if you are going up there.

The only alternative would be Batts that can be moved out of the way when needed.

Bud


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## Alketi (Dec 20, 2015)

I'm planning on keeping a catwalk in my attic center section and adding much more insulation to the edges.

To keep the blown-in insulation at bay, I plan on taking 4x8' plywood and ripping it down to 4 strips of 16", and using it to make a wood dam. 

I'll then attach the plywood strips to the joists with metal L-brackets at every joist intersection. The brackets would be something like these: http://www.homedepot.com/p/Everbilt-4-in-Zinc-Plated-Corner-Brace-2-Pack-15309/202033899

Very easy.

You also want to insulate and air-seal your hatch cover. Here's one of the many ways to do it:


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## ChuckF. (Aug 25, 2013)

"Can you describe how to build a wood box around the opening. I usually use a small step ladder, hold onto the sides and pull myself up. My concerned is if I build a wall I will need a longer ladder to reach the sides. Also the wall I build likely won't support my weight."

I did something similar, built a wood box with 1/2" plywood, but I spaced it away from the 2x10 framing of the hatch on two sides with another 2x. That way I was still able to use the 2x10 hatch framing to step on.

In my attic layout I don't have to use the hatch to pull myself up, because I can reach a 2x4 part of one of the trusses. You might be able to put something in to grab onto higher up.


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