Community: Building Code Questions

Q & A Instructions

[Click map to enlarge]

The GBAGreenBuildingAdvisor.com web site has a wealth of articles on a wide variety of construction topics. Before posting your question, you may want to check out the articles on this page: How To Do Everything. You just might discover an article there that provides the information you seek.

Please register for a free account or sign in to ask and answer green building questions.

If you want to post a question, the usual rules of courtesy apply:
1. Be nice.
2. If you can't be nice, be polite.
3. If you can't be nice or polite — well, please be brief.

To attach a photo or illustration: Under the box labeled “More explanation,” look for the words “File attachments.” Click that, and you should be able to attach a photo.

Thanks for joining the conversation!


10 Answers

Anybody familiar with British Columbia building codes?

I am building a home in BC, and plan to use Lunos e2 for my HRV. There is a lot of stuff about ventilation and HRV in the latest code revision (Dec 2014, I believe). Is there, by any chance, anybody out there familiar with the BC codes that can tell me if I am going to experience issues trying to use the Lunos fans?

A couple things that I am concerned about (off the top of my head).

Asked By Stephen Youngquist | Jul 29 15
2 Answers

Steel Quonset hut — 1 hour fire rating?

Hello,

Asked By J Choi | Jul 31 15
5 Answers

Insulation for condensation control changes from IRC 2009 to 2012

I'm building a small house in Portland Oregon, climate zone 4C marine (according to 2009 IRC). I have 2x12 rafters with blown cellulose, then a layer of taped plywood sheathing for air barrier, then 3" of XPS followed by another layer of ply and the roofing on top of that. Since the ceilings are vaulted, it's an unvented attic situation, so I'm worried about moisture. I've got R36 in the cellulose and R15 in the XPS.

Asked By Tom Frisch | Jul 26 15
20 Answers

Buyer education versus a good code and intensive enforcement of it

This is kind of a general question. I'm seeing more and more issues coming up on GBA questions and answers regarding shoddy construction that homeowners are having to deal with. I read it recently in Peter L's description of some builders in the Phoenix area. This is most concerning when one is having a new home built, or purchasing a previously built new home, and it has subpar construction.

Asked By Eric Habegger | Jul 21 15
3 Answers

Do I need to cover XPS in an attic?

I know codes vary from town to town but I'm looking for the general code requirement/interpretation for this. I have used R-10 2" XPS for the interior of basement walls. I know that it must be covered with drywall or another similarly accepted material for compliance and I have done so. I also have learned that the exception is between floor joists at the rim joist and have benefitted from this exception...wouldn't that be a pain of a detail! I now have to build an enclosure that had never been built for a fire box that protrudes into the attic over the garage.

Asked By Tyrone Powell | Jun 22 15
4 Answers

Insulating the Interior of Poured Basement Walls

This picture is from building science.com and shows an ICF foundation with insulation under the slab. My question relates to the interior wall plane where the floor slab meets it. Does the code require that the slab make physical contact with the concrete wall? If it does, how do code officials deal with situations like this one with ICF foundations? I wanted to have a similar insulation setup on the interior with poured walls. Prior to pouring the floor I would lay rigid foam along the ground and up the wall - thermally isolating the slab.

Asked By Brian W | Jun 21 15
1 Answer

Is this 2012 code already enforced for TX ? - whole-house mechanical ventilation system

Is the requirement of "whole-house mechanical ventilation system" for Code 2012 already being enforced in TX ?
Is it mandatory in the state of TX now ?
If so, can you send me copy of that section for Code 2012 or which website to locate it please ?

Thank You,

Darla Kay

Asked By DARLA KAY | Jun 18 15
3 Answers

Is tape permissible between framing and the party wall for air sealing?

We are building a Passive House duplex and have encountered bunch of air leakage around party wall. We don't have to reach Passive House standard for each of the units separately, only as a whole building. But currently, our party wall does not have any air seal crossing between two units. This opens up the possibility of air getting in somewhere at the top end of it (at the roof) and traveling down to edges of the party wall touching the whole building enclosure/exterior plywood. We have difficulty sealing these vertical contact points due to other framing being in the way.

Asked By Lucyna de Barbaro | Jun 12 15
2 Answers

Toilet stack alternatives

I've recently realized that air admittance valves have generally become
more permitted by code and help reduce the number of roof penetrations,
but they likely still won't do for a sealed system [on-property septic]
as any positive pressure has to have *somewhere* to go. Thus, as far
as I know code only permits AAVs for branches but not the main stack;
there has to be *someplace* for the sewer gas and its attendant
condensation to escape. [Is that also true for systems piped into
city sewers, which would eliminate the pressure problem?]

Asked By Hobbit _ | Jun 10 15
2 Answers

No footing, no drainage?

Yesterday I was excavating a corner of my house to add Roxul to the exterior of my slab on grade foundation walls to help with my hydronic heat problems.

To my amazement, I found a section the foundation wall that has no footing. It is where the garage footing meets the house foundation wall. There is a corner and the house side of the foundation wall is missing a footing for about 2 feet. After this you can see the wood they used to form it go back below grade where I'm assuming a footing starts for the rest of the wall.

Asked By Michael McArdle | May 27 15
Register for a free account and join the conversation


Get a free account and join the conversation!
Become a GBA PRO!