with greenbuilding in mind, how much caulk is too much? we have been instructed to seal all stud seams on the interior of a new structure. For example, there are four studs making a 6x post and the boss wants all the seams (where each stud is attached to the next..making the post) to be sealed with caulk on the interior. Is there some sort of info/specification about sealing the structure when “building” green? Can the structure become too air tight? Is this just a waste of caulk?
Discussion Forum
Discussion Forum
Up Next
Video Shorts
Featured Story
Tips for protecting your personal information when using Wi-Fi-connected devices.
Featured Video
How to Install Exterior Window TrimHighlights
"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.
Replies
>> Is there some sort of info/specification about sealing the structure when "building" green? << A blower door test is done to ascertain the "air tightness" of the structure. You may want to check the VOC content of the caulk you are using though to be sure that indoor air pollutants aren't being introduce in excessive amounts.
>> Can the structure become too air tight? << Yes. Tight buildings have to be augmented with controlled ventilation. The idea is that supplemental ventilation, often supplied through the HVAC system, is balanced with the thermal envelope leakage.
>> Is this just a waste of caulk? << Maybe... Caulk is pretty cheap though. And it is the kind of thing that can't be added later.... The Energy Star people here (where I live) want any double stud with a crack between caulked. I guess that one could argue that double, triple, etc studs can form gaps in them as the framing materials dries to it's fullest extent.. It it might seam a little more sensible to caulk studs to the sheathing that cover the joints in exterior wall sheathing,,, Don't slam him for wanting to build a better house though. We are in a learning evolution...
Edited 8/21/2009 8:47 pm ET by Matt
right, but there is house wrap, plywood, surrounding windows and trim (all solid trim -from window to window- what benefit comes from caulking interior? The idea doesn't sit well w/ me. Is this common practice?
I added to my initial post.
The idea is to limit air circulation within the wall cavity. And - Yes it is common practice - in high performance homes. At the minimum the joint where the wall bottom plate sits on the subfloor should be caulked if the house is to be other than "run of the mill". Ever noticed in a room of an older house where the carpet was dirty all around the edges - especially on the exterior walls? That is caused by air infiltration.
I get what your saying, but all vertical seams were caulked on the exterior before the wrap and ply went up...I am not talking about issues like air coming in near elec box, etc. I am talking about interior side of a constructed post. So, you are saying it is common to caulk all interior seams...i can't wrap my head around how air will pass through a solid section...but it is good to know this is what is working for others, thanks
Caulking stud columns is a little on the overkill side - assuming KD lumber and no gaps between the studs.
>> I get what your saying, but all vertical seams were caulked on the exterior before the wrap and ply went up<< If you are saying the double studs were caulked on the outside, before the sheathing was installed, I've never heard of that before... Not saying it is bad - just not heard of that being done.
Is this house to be energy Star Certified or similar?
Is this your bosses personal house? That might expain the over the top methds...
If you read this posting about installing fiberglass batts, in the scenario I presented there, you can see the problem (hopefully) with air leakage through the wall assembly. To add to that scenario, I'll say that actually the sheetrock often doesn't sit tightly against the stud faces, meaning that cold air leaking in from any source has the potential of creating entire cold areas on the back of the sheetrock. RE the sheetrock not sitting tight against the studs - I think in another thread you said you have experience at doing trim carpentry. How many times have you seen a 4 9/19" window or door jamb be NOT be flush with the inner surface of the drywall?
Edited 8/22/2009 10:00 am ET by Matt
PS - since you are a newbee let me mention something... Here at BT, there is a folder called "Green Building" or similar. You should see the folder list shown on the left side of your screen (depending on what view you are using) with a scroll bar. If you had posted in "green building" your Q may not have been answered quite as quickly, but your topic would enjoy a longer life and you might get more opinions from the people who are really into Green Building, the tree huggers :-), since they undoubtedly spend time in the green building folder reading every thread.... This topic will probably be off the bottom of the "general discussion" list in a week or so.
And a side comment - really this is as much an "energy efficient construction" topic as it is "green" topic. Granted, energy efficient construction is one of the basic building blocks of green building....
Pardon the intrusion, but you have been given a lot of "reasons why" and it sounds like you just do not want to do the work. As I have said to the carpenters that worked for me when hurricane strapping came into Fl, "you get paid the same $/hr to frame the wall or put on the hurricane straps. What is your problem."