Suggested materials for exterior attic crawlspace access door.

Hello,

I want to create an access to the attic crawlspace via door in the gable end of the house. I want to disguise it to look like a gable vent. To add to the challenge, I want an "eyebrow" (i.e., arch at the top) shaped door.

I'm thinking of using exterior plywood--perhaps reinforced on the backside with angle aluminum to inhibit warping. On the face, I'll use PVC to (somehow) fake the look of a gable vent.

In case you're wondering, we currently have an access door in the ceiling of a room that we'd like to finish as a living room, so we'd like to finish the ceiling. We have limited closet space and the closets are crowded and shallow, so they have been ruled out for locations for the access door.

I welcome any suggestions.

Thanks in advance.

 

Have you checked to make sure there isn't a stud where you hope to install the door? Could you buy a gable vent and then build a plywood door to attach it to? IMO wood 2xs on the back side is plenty to prevent warping.

 

Thanks @marksr.
I did talk with a town code inspector who said I'd need to frame it out with a header, just as if I were doing a new construction window or door. There is a (sideways) stud there that I will have to move.
The other limitation the inspector gave me relates to your question about whether I'd considered using a pre-made vent. My clear opening needs to be 22"x30". That's bigger than most vents and I haven't found a pre-made that would work along with the hinges I'd need to attach.

 

You could fashion it so the door and frame are a 'frame' for the vent.

 

Thanks again @marksr.
Fashioning a "frame" may be the way to go. In my case, I'll probably end up with a frame within a frame. I already planned for creating a frame that would attach to the exterior sheathing--I need that for the Hardie planks to abut to and be sealed against. I'll probably need an interior frame though too--one that moves with the door--in order to fill out the dimensions for that 22" x 30" requirement.

Here is a Fypon decorative louver that I'd love to use


The problem with that one is that it is urethane and I'm afraid the woodpeckers in my neighborhood would destroy it. Woodpecker damage is the main reason I set out to replace all of my cedar shake siding with Hardie.

 

Hi Sturdy,
That's a big vent, can it be smaller?

Bud

 

Hi Bud,

I surely do wish it could be smaller. I don't know if you saw my note to @marksr, but the town code inspector said my clear opening has to be 22" x 30".

 

We can run the numbers and see if he is right, but there is a LOT of wiggle room and if there are other vents then I suspect smaller would work and we may be able to convince him.

This is a high attic vent?

What other vents are up there, high and low?

Is his number 22"x30" a NFA (net free area) number, meaning the size is larger to account for the loss from screening and louvers.

What is the height from the low vents to the top of the high vent?

Is your attic well air sealed and do you have a vapor barrier next to the drywall. If no vapor barrier, a good specific paint would do. VB and sealing cut the vent area from 1/150 down to 1/300.

But, if you have more soffit venting than required you are allowed to decrease the high vent area to a 60% low and 40% high. Even as much as 75% low and 25% high can work, just not published.

I need your attic floor space, attic height, and other details asked above.
And, there are other options.

Bud

 

Hi Bud,

I see where you're going now. I don't really need or want it to be a vent at all.
I have soffit and ridge vents.
I just want it to "look" like it could be a functioning gable vent.
I need a door, not a screen :-)

Thanks.

 

LOL, then that explains the size, seemed awfully large.

A good laugh always feels good even when I'm laughing at myself.

Bud