In renovating a 100 year old house, we needed a safe work platform in the attic to remove 4 giant old chimneys. We beefed up ceiling joists (sistering 2×10’s to old 2×4’s on 24″ centers with 12′ spans). Installed a ladder-type attic access and nearly died carrying up 4×8 sheets of 3/4″subfloor plywood to cover about 75% of the attic where we would need to set up ladders and scaffolding. Well, the t&g of the plywood just wouldn’t fit together. Old house, lots of wiggles, not a flat plane in sight. We figured WTF, it’s not a living space, so we cut off the tongues and screwed everything down. Took down the chimneys and plan on blowing in 14″ of insulation over everything. Well, the building inspector just made a passing comment that he expects there to be T&G subfloor up there since there’s now flooring up there and an attic access.
We don’t plan on using the space for storage. It will be covered with blown in insulation and the house is huge and doesn’t need additional storage. I’ve poured over the IRC-2018 and cannot find anything that confirms what the inspector said. I don’t want to fight him but don’t want to die taking the subfloor sheets back out either. I know a normal subfloor must have t&g or land on joists… but in an attic covered with insulation???
Long story short… Where in the IRC can I find what kind of flooring is allowed/required in an attic? What makes an attic considered usable for storage and does that automatically necessitate proper/ t&g subflooring? What are my options, if any? Thanks in advance
Replies
You may consider removing the ladder and revert to a smaller access hole.
If you can communicate with the inspector or zoning office, they might be happy with this, and it would make sealing to reduce airflow easier. They may have other suggestions if you make it clear you do not plan to leave it suitable for storage. The object is to have a conversation, not a fight.
I'd hate to do that if not necessary.You're right... it's not a fight at all - it's not an adversarial relationship whatsoever. Generally, when I politely ask him to reconsider something based on IRC section blah blah, he's really cool and doesn't seem to mind. Was hoping to find that miracle section in the code book
https://up.codes/s/floor-sheathing my quick google found this link.
Looks to me like if you have 3/4 inch, you should be ok. (but I am not the inspector)
Orientation comes into the picture as well, but looks to me like it should be good.
That's the chart that I used to justify the rest of the house that has 1" old oak flooring without any subfloor beneath it - it saved us thousands!! Unfortunately, in the attic, we used OSB sheets, not lumber
Ah yes, Guess I did not read close enough.
Maybe you can add a layer of 1/4" and stagger the seams to keep the inspector happy
I will ask him what's allowed. Was just hoping there was something in the code