Insulate Between 4' OC Joists - Insulation - DIY Chatroom Home Improvement Forum

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


Thread Tools Display Modes
Old 07-26-2011, 12:08 AM   #1
Join Date: Jul 2011
Posts: 1
Rewards Points: 10

Insulate between 4' OC joists

My 1969 rambler has 3x10s 4' on center with 2x6 car deck t&g subfloor. I had R-30 unfaced fiberglass batts in between held by twine strung across and stapled. Rats had got up on the insulation and made condos and a social club till I bade them farewell. Now I have these expansive joists and nothing solid to span the 45-1/2" tween the joists. Is spray foam the only choice? There is about 24"-30" from ground to joist and no center beam in 24' of joist span. I live near Seattle so we get a fair amount of ground moisture, too. What's the best route?


JeRemodel is offline   Reply With Quote
Old 07-26-2011, 01:18 AM   #2
Join Date: Mar 2011
Location: Ohio
Posts: 1,646
Rewards Points: 1,000

what about fiberglass with chicken wire over it. maybe tyvec would work for you.


DannyT is offline   Reply With Quote
Old 07-26-2011, 06:20 PM   #3
Join Date: May 2009
Location: New England
Posts: 23
Rewards Points: 10

First off let me say I don't really like foam for a number of reasons I am a cellulose guy but this seems like an ideal spot to use foam. I have in the past blown cellulose into a floor like that but it had plywood on the bottom already and was in a fairly dry area. They do make a PSK faced fiberglass product kinda like duct wrap that you can get made almost any size but it is not cheap and it's a special order. It is usually held up with stick clips and or wire . It being fiberglass it is subject to the rat thing also.
parts is offline   Reply With Quote
Old 07-27-2011, 10:18 AM   #4
AGWhitehouse's Avatar
Join Date: Jul 2011
Posts: 1,378
Rewards Points: 500

With spray foam you will have to cover it with an ignition barrier and a thermal barrier (if it's not code for you now, it will soon be). So along with spray foam comes the need to sheetrock the space. And since you have such large spans that would also entail additional framing.

So I would suggest what DannyT proposed: batts of some sort with chicken wire and tyvek. Chicken wire for the rats, tyvek for the air barrier. If moisture is a problem, lay down some 6 mil plastic on the floor of the crawl space and it will help reduce the overall moisture levels.
Life's too enjoy it!
AGWhitehouse is offline   Reply With Quote
The Following User Says Thank You to AGWhitehouse For This Useful Post:
tpolk (07-27-2011)

Thread Tools
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
Insulate basement header with imbedded joists??? lackofunds General DIY Discussions 21 04-17-2011 03:41 PM
Pot Lights?? Installed in floor joists.... Can u insulate around them?? garyroney Electrical 8 04-08-2011 11:18 PM
Best way to insulate engineered joists? sheslostcontrol Green Home Improvement 0 02-23-2011 09:25 PM
Bubba's been here. Repairing sagging rim/floor joists. MattFels Building & Construction 7 02-09-2011 05:28 PM
Necessary to insulate basement ceiling between joists? yummy mummy Building & Construction 12 02-06-2009 11:19 PM

Top of Page | View New Posts


Search Engine Friendly URLs by vBSEO 3.6.1