Insulating Rim Joist - Questions. - Insulation - Page 3 - DIY Chatroom Home Improvement Forum
Advertisement


Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Insulation

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread
Display Modes
Old 11-17-2014, 02:51 PM   #31
Member
 
Join Date: Sep 2014
Location: Cook County, IL
Posts: 693
Rewards Points: 1,099
Default


Just wondering if an elastomeric caulk is needed such as >

http://www.homedepot.com/p/HDX-10-oz...1-66/204852647

or

http://www.homedepot.com/p/DAP-Dynaf...275/100035980#

Just want to make sure I use the right stuff that won't crack.

I noticed under specifications that the two caulks above say "yes" under permanently flexible.

Whereas the Alex Plus says "no" under permanently flexible.

http://www.homedepot.com/p/DAP-Alex-...8103/100097524

Wouldn't I want something flexible? (Elastomeric)

Last edited by cjaustin81; 11-17-2014 at 02:57 PM.
cjaustin81 is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 11-17-2014, 04:04 PM   #32
Member
 
Join Date: Sep 2014
Location: Cook County, IL
Posts: 693
Rewards Points: 1,099
Default


After researching the problem these are the products I plan to use:

1) Dynaflex 230 10.1 oz. Premium Indoor/Outdoor Sealant - The reason I chose this over Alex caulk is because this caulk is permanently flexible, meaning it can bend without cracking as the weather changes. On the package it also lists:

"It has excellent adhesion to a wide range of building materials including wood, MDF, PVC, polystyrene, and composite trimboard."

So it specifically lists polystyrene (rigid foam).

http://www.homedepot.com/p/DAP-Dynaf...8275/100035980

2) Loctite® PL 300® VOC Foamboard Adhesive - I chose this because you need to be careful with adhesives used on polystyrene. This product is specifically marked as being compatible for use with polystyrene.

"PL® 300 VOC is a latex-based adhesive especially designed for bonding polystyrene foam to itself or to a variety of construction materials, including, but not limited to: wood"

http://www.loctiteproducts.com/p/pl_...d-Adhesive.htm

3) R15 Rolux - To safely create a fire-barrier in front of the XPS foam.

Does this seem legit? I'm glad I took the extra time to figure out the correct caulk/adhesive to use BEFORE I started the job.
cjaustin81 is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 11-17-2014, 06:42 PM   #33
Member
 
Join Date: Nov 2009
Location: west of chicago
Posts: 470
Rewards Points: 426
Default


Get the large size 28oz? vs 10 oz? caulk gun as you'll save a bunch buying the larger
tubes.
This time of year ....... I'm thinking the PL300 needs to be above 40f to cure....wondering what the band temp might be after it's covered.
PL Premium may be the ticket for these cold temps lately at least behind the foam.
I've got more premium than 300 on my foam walls ...little pricier but lots stronger.
Single digits tonight ....plowed the driveway yesterday ..what the heck.
High Gear is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 11-17-2014, 07:20 PM   #34
Member
 
Join Date: Sep 2014
Location: Cook County, IL
Posts: 693
Rewards Points: 1,099
Default


My friend just reminded me of something that's going to dictate the direction of this project. This past summer I had MOLD in the basement and I had to do a mold remediation.

With that being said, my friend told me I shouldn't use ANY caulk for this job and I should also skip the glue (since both can grow mold).

What are your thoughts on this? He indicate that I should use Great Stuff since that can't inhibit mold, is this true?

Mold prevention is my #1 issue in my basement so any help in regards to that would be appreciated, thanks.
cjaustin81 is offline   Reply With Quote
Old 11-17-2014, 07:23 PM   #35
Member
 
Join Date: Sep 2014
Location: Cook County, IL
Posts: 693
Rewards Points: 1,099
Default


Quote:
Originally Posted by High Gear View Post
Get the large size 28oz? vs 10 oz? caulk gun as you'll save a bunch buying the larger
tubes.
This time of year ....... I'm thinking the PL300 needs to be above 40f to cure....wondering what the band temp might be after it's covered.
PL Premium may be the ticket for these cold temps lately at least behind the foam.
I've got more premium than 300 on my foam walls ...little pricier but lots stronger.
Single digits tonight ....plowed the driveway yesterday ..what the heck.
I'm concerned about mold growing on any caulk and/or the PL300 glue.

Do you know if Great Stuff is a mold-free product?
cjaustin81 is offline   Reply With Quote
Old 11-17-2014, 07:46 PM   #36
Member
 
Join Date: Nov 2009
Location: west of chicago
Posts: 470
Rewards Points: 426
Default


Just wait for warmer temps for the install should be some yet this fall.
Run a dehumidifier in the basement during the summer months and don't over humidify during the winter .
High Gear is offline   Reply With Quote
Old 11-17-2014, 07:49 PM   #37
Member
 
Join Date: Sep 2014
Location: Cook County, IL
Posts: 693
Rewards Points: 1,099
Default


Quote:
Originally Posted by High Gear View Post
Just wait for warmer temps for the install should be some yet this fall.
Run a dehumidifier in the basement during the summer months and don't over humidify during the winter .
I'm not worried about the install, I'm worried about when summer comes and the humidity is high. I'm now running a 70-pint dehumidifier.

For my situation, I'm wondering if using Great Stuff would be better than a mold resistant caulk to seal the rigid foam and make it air tight?
cjaustin81 is offline   Reply With Quote
Old 11-17-2014, 09:22 PM   #38
Member
 
Join Date: Sep 2014
Location: Cook County, IL
Posts: 693
Rewards Points: 1,099
Default


Stupid question, but do you have to install the XPS foam in a specific direction (ie. so the text isn't upside down)?

Or can I cut a mix of upside down and sideways pieces?

The reason I ask is I have 2ft x 4ft pieces and I can get 8 squares vs 6 if I don't have the text all facing normally.

This would be for code reasons.
cjaustin81 is offline   Reply With Quote
Old 11-17-2014, 09:37 PM   #39
HDS
Member
 
Join Date: Jun 2014
Location: Southwest Ohio
Posts: 405
Rewards Points: 330
Default


The direction shouldn't matter. Instead of glue you could use long screws or nails with caps to hold the xps foam in place..

Before putting the xps in place, caulk around the perimeter to air seal each bay.

Also don't forget to seal the sill plate and concrete too.
HDS is offline   Reply With Quote
Old 11-17-2014, 09:48 PM   #40
Member
 
Join Date: Sep 2014
Location: Cook County, IL
Posts: 693
Rewards Points: 1,099
Default


Quote:
Originally Posted by HDS View Post
The direction shouldn't matter. Instead of glue you could use long screws or nails with caps to hold the xps foam in place..

Before putting the xps in place, caulk around the perimeter to air seal each bay.

Also don't forget to seal the sill plate and concrete too.
Because I had mold in my basement this past summer I'm going to try and avoid any caulk. I'll use the Great Stuff foam instead. I think this makes sense.

I was thinking if I use XPS and then seal it AFTER, that should be good enough. I'm worried if I seal it first I won't get a nice flush seating w the wood rim joist.
cjaustin81 is offline   Reply With Quote
Old 11-17-2014, 09:53 PM   #41
Member
 
Join Date: Sep 2014
Location: Cook County, IL
Posts: 693
Rewards Points: 1,099
Default


Quote:
Originally Posted by HDS View Post
The direction shouldn't matter. Instead of glue you could use long screws or nails with caps to hold the xps foam in place..

Before putting the xps in place, caulk around the perimeter to air seal each bay.

Also don't forget to seal the sill plate and concrete too.
I'm not going to secure the XPS to the wood, I don't see any reason to do that if I can trim it and seal it with foam.

That's a code requirement for commercial buildings not residential.
cjaustin81 is offline   Reply With Quote
Old 11-17-2014, 11:58 PM   #42
HDS
Member
 
Join Date: Jun 2014
Location: Southwest Ohio
Posts: 405
Rewards Points: 330
Default


Excess moisture is what causes mold. Have you determined what was the source of moisture in your basement?
HDS is offline   Reply With Quote
Old 11-18-2014, 12:06 AM   #43
Member
 
Join Date: Sep 2014
Location: Cook County, IL
Posts: 693
Rewards Points: 1,099
Default


Quote:
Originally Posted by HDS View Post
Excess moisture is what causes mold. Have you determined what was the source of moisture in your basement?
I wasn't running the AC or a dehumidifier in the summer.
cjaustin81 is offline   Reply With Quote
Old 11-18-2014, 05:51 AM   #44
MEASURE ONCE, CUT TWICE
 
123pugsy's Avatar
 
Join Date: Oct 2012
Location: MARKHAM, ON
Posts: 4,306
Rewards Points: 1,778
Default


Instead of worrying what mold grows on, you should be concentrating on sealing up, with caulk, all air gaps so the moist humid air from outside doesn't get in in the first place.

If your conditions are such that mold will grow on caulk, it will grow elsewhere. So now you have no caulk with mold, but you will have mold in other places.

Fight the moisture.

How about your walls below the rim board? How are they finished?
123pugsy is offline   Reply With Quote
Old 11-18-2014, 06:59 AM   #45
Member
 
Join Date: Sep 2014
Location: Cook County, IL
Posts: 693
Rewards Points: 1,099
Default


Quote:
Originally Posted by 123pugsy View Post
Instead of worrying what mold grows on, you should be concentrating on sealing up, with caulk, all air gaps so the moist humid air from outside doesn't get in in the first place.

If your conditions are such that mold will grow on caulk, it will grow elsewhere. So now you have no caulk with mold, but you will have mold in other places.

Fight the moisture.

How about your walls below the rim board? How are they finished?
But a Great Stuff also seals air gaps and has a higher insulation value than caulk
and also better for mold. Unless I'm missing something where caulk would be
somehow better in this application?

It's an unfinished basement do below the rim joists are concrete
foundation walls w nothing covering them.
cjaustin81 is offline   Reply With Quote
Sponsored Links
Advertisement
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Insulating Rim joist help word2yamutha Insulation 9 03-13-2014 02:00 AM
Rim Joist inaccessible. darklightwarrio Insulation 10 01-13-2014 09:02 PM
Insulating Rim Joist - caulk or spray foam around edges? markley Insulation 14 01-15-2013 12:41 PM
Insulating a basement wall have questions. kossuth Insulation 9 08-09-2011 10:04 PM
Crawl Space Beam and Joist Support Questions Fire4Effect Building & Construction 5 06-28-2009 01:07 PM




Top of Page | View New Posts