SPI quote for 3" OC703 and Roxul Rockwool

Post by **Aaronw** » Thu Sep 16, 2004 7:35 am

How large of a room or rooms are you building?

Shaz · Post by **Shaz** » Thu Sep 16, 2004 7:48 am

Look at the layout. I think one tube covers about 40 linear feet, so I might be able to get away with two cases? What do you think?[/img]

Post by **Aaronw** » Thu Sep 16, 2004 7:57 am

40 linear feet. Hmmm... That might be for a typical straight line at 1/4" bead. Keep this in mind...I'm assuming you're using 5/8" drywall. And although the gaps are only 1/4", you'll probably still use more of it. Some gaps sometimes end up a little bigger, some a little narrower. When you start doing corners, etc or the vertical joints, you'll find the caulk will go much further back into the wall. Sometimes requiring to go over it a second time just to fill the void. That's been my experience.

I did however, in a few spots when I put up the ceiling, the room wasn't square, the board had about a half inch gap in a small section. I went to HD and picked up some "polyfoam caulk saver" which comes in different sizes, and put it up first to fill the crack, then caulked it. Worked great.

dk01 · Post by **dk01** » Fri Sep 17, 2004 4:25 am

Great tips and info on caulking - thanks Aaron...

What would you say is the linear feet of a 29oz. tube of acoustical caulk at your recommended/experience using it at the bead size you are etc.? Is it more like 20 linear feet sans corners etc.?

I have an interior unfinished space of 22' x 10' x 9'+ height - that I need to caulk the interior of the exterior sheathing (its a garage with an exterior sheathing of some sort of wood tongue and groove 1"), its unfinished so I have the opp. to do this before filling with Roxul and finishing off with drywall layers and more caulk etc.

Big question too is - SHOULD all the seams between batts and around edges of batts and studs be sealed also?

I was thinking of buying 9 cases (9x12) or 108 tubes to start - figuring I have a few interior walls to build w/ double layers of drywall etc. and lots of ceiling things to extra caulk...

Sound like way too much or too little still?

thanks

David

Post by **Aaronw** » Fri Sep 17, 2004 6:08 am

In my case, I was using steel studs (which are prepunched for electrical runs), and I used RC1, so cauking that in my case, wouldn't have made a difference. I did caulk under the bottom track though to reduce flanking.

If your using wood, I've seen several pictures where everyone has sealed at every stud at the top and bottom plates.

As far as the amount of sealant used per linear feet, it's been anywhere from 15-30 I would guess. Corners is where I used the most caulk. Two corners (if that) at 86" high, I quickly used up a tube.

Shaz · Post by **Shaz** » Fri Sep 17, 2004 6:31 am

This drawing shows where to caulk. I was planning to follow this and then if I needed to caulk any other spots then I was planning to do it as I go.

dk01 · Post by **dk01** » Fri Sep 17, 2004 6:48 am

Yeah that drawing is what I am basing my stuff off of - but, does the insulation (safb or 703,705) remain freely placed in the cavity?

As this Jack Piercy Acoustech fellow stated: you must "seal" the pieces of insulation together and to the studs to create it basically airtight... which I had never heard of INSIDE a wall cavity...

He also stated 2" Rigid affixed at the front of the studs and leaving 1.5" inch air gap... hence why the idea of sealing might make sense in his recommendation...

But, I have never heard doing this or the advantages of this type of wall construction/insulation (I think I highjacked this thread - sorry)

David

Post by **Aaronw** » Fri Sep 17, 2004 7:24 am

I'll add a new piece of info that I learned recently from my drywall friend. If you are using RC or hat channel, according to firecodes, that airgap between the stud and drywall must have insulation. The keeps (if you have a fire) from climbing up behind the drywall and up...

Post by **Aaronw** » Fri Sep 17, 2004 7:48 am

Shaz,

Would be so kind as to "shrink" that last pic. It's huge...

Shaz · Post by **Shaz** » Fri Sep 17, 2004 11:21 am

Fixed, sorry

BTW, I am not using RC since my concrete walls have insulation attached to it already. I will leave about 1" air gap between the concrete walls and the new 2x4 stud walls to get a two leaf wall

David, my understanding is that you don't need to caulk the insulation to the studs, but make sure that the insulation is filled between the studs really tight so that there is no gap left between it and the studs. Guys, please correct me if I am wrong!

Shaz · Post by **Shaz** » Sat Sep 18, 2004 5:15 am

OK, just picked up 4 cases of caulk, A&I didn't give me any discount though, They said they quoted me the price by case quantity

Anyway, it's a great place. If you are in Chicagoland area, you can buy most of the stuff from them. They carry caulk, Roxul insulation and Neoprene.

I also saw some cool cieling grids (curved, rectangle or triangle shaped) for drop ceiling or hanging drop cieling over drywall made by USG. These can be used to install diffuser cieling tiles.

dk01 · Post by **dk01** » Sat Sep 18, 2004 10:57 am

Cool on your caulk experience - I just went to pick up my order for 8 cases of USG at WHITE CAP DIRECT (purchased through the website) picking up at local San Jose outlet and THEY tried to substitute the OSI stuff at the same price. I was less familiar with it and kinda thought it was cheaper, but they just said thats the deal. THEY are very unintegrated between web and outlet and felt it was ok to not let the customer know beforehand that they would be sub'ing something. I was getting it for $3.51 a 29oz. tube. I opted to not take the order.

I was not familiar with the wider temp. band with the OSI - maybe I should of taken it.

I am not very pleased with WHITE CAP DIRECT at all really after that. I guess I will try CalPly next week. Sucks - cause I had planned to begin work tomorrow.

Maybe 3.51 is too high anyhow for caulk.

Shaz what brand and what did you pay in Chicago?

Best Regards,

David

Shaz · Post by **Shaz** » Sat Sep 18, 2004 11:43 am

I bought titebond @ $4.25/ 29oz tube

Kind of pricey ... $3.51 for OSI was a pretty good deal IMHO

Post by **Aaronw** » Mon Sep 20, 2004 9:05 am

This last case I bought was OSI. It seems to be working out just fine. I've had the chance to finally use about 2/3rds of the case. $3.51 isn't a bad price. I paid $3.25 a tube.