Installing Insulation Under Addition. - Building & Construction - Page 2 - DIY Chatroom Home Improvement Forum


Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Building & Construction

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

Reply
 
Thread Tools Display Modes
Old 06-29-2010, 01:56 PM   #16
Member
 
Join Date: May 2008
Location: Rochester, NY
Posts: 208
Rewards Points: 150
Default

Installing insulation under addition.


I grew up in a mobile home trailer and your pics remind me of a funny story that happened when I was a kid.

Under the trailer there was fiberglass insulation, same as yours and instead of paper vapor retarder there was a geotextile material that helped to protect the insulation form the outside. We had a pregnant cat that managed to rip out some material and have her kittens snuggeled up in that warm fiberglass insulation as it was the middle of winter. We kept hearing meowing from our bathrrom vent and it took my dad weeks to firgure out where the kittens were

Just something to consider, that fiberglass looks very appealing to critters wanting to stay warm if you have cold winters.

Advertisement

creamaster is offline   Reply With Quote
Old 06-29-2010, 02:41 PM   #17
Newbie
 
Join Date: Jun 2010
Posts: 12
Rewards Points: 10
Default

Installing insulation under addition.


Definitely a funny story!! I plan to cover it up using either polystyrene foam or plywood over the insulation in order to keep the varmints out. The cost difference is only a few dollars more for the plywood but installing the foam would be much easier since I will be doing it alone. My only concern like I said before is whether or not the foam is a severe fire hazard (again not that I plan on starting a fire underneath my porch ). I'm going to talk to the people at lowes again and see what they say. I pulled out the old insulation today and was amazed at how much mold there was against the paper backing. At least there was no mold growth on the wood beams!!
gillaustin316 is offline   Reply With Quote
Old 06-29-2010, 03:21 PM   #18
Newbie Bill
 
Join Date: Dec 2008
Location: Alberta, Canada
Posts: 1,056
Rewards Points: 500
Default

Installing insulation under addition.


I think you are on the right track by pulling the old insulation out. I personally would cover it with plywood. Use a car jack or something similar to hold the plywood against the joists until you get it fastened.

I strongly suggest you confirm the advice from Lowes with the guys here before implenting.

Guys, should this situation have a vapor barrier at the floor, or is the floor itself a vapor barrier?
__________________
Bill

A DIY Noob that knows just enough to be dangerous.

Last edited by drtbk4ever; 06-29-2010 at 03:23 PM.
drtbk4ever is offline   Reply With Quote
Old 06-29-2010, 07:28 PM   #19
Newbie
 
Join Date: Jun 2010
Posts: 12
Rewards Points: 10
Default

Installing insulation under addition.


I stopped by Lowes again tonight and spoke to one of the guys who works in the area where the contractors gets their supplies. He agreed that the polystyrene foam might be too flammable even under the deck where there would be few ignition sources. He pointed out another style of insulation board (of course I can't remember the name and the paper I wrote the information on can't be located at this moment ) that is far less likely to burn. I'm still in the planning stages and have made no final decisions as of yet.
gillaustin316 is offline   Reply With Quote
Old 06-29-2010, 07:31 PM   #20
Newbie
 
Join Date: Jun 2010
Posts: 26
Rewards Points: 25
Default

Installing insulation under addition.


That setup you have existing is a recipie for disaster.

Vapour barrier should be on the warm side always. New batt insulation should suit your wood configuration. Rigid Mineral wool and an air barrier may prove to be useful. (a little more expensive but I would think it would be more suitable here as it is moisture and inherantly fire resistant).

I might uninsulate the deck area and buy a nice set of french insulated exterior doors between the house and the deck.

Check your local C & D facility on disposal of insualtion.

Another thought using rigid insualtion (r-20) @ u/s of deck perimiter insulate & tuct tape seams.

The main thing is right now your gonna get mold issues & pest issues (mice or bugs) living in your insulation

Just a thought
Bldg 2 Spec is offline   Reply With Quote
Old 06-29-2010, 08:19 PM   #21
Member
 
Join Date: Jan 2009
Location: South of Boston, MA
Posts: 17,248
Rewards Points: 2,000
Default

Installing insulation under addition.


Based on the pics I'd close in the whole area with outside walls
Looks like you only need 2 walls ?
Make a panel removeable for access
Put 6 mil plastic down on the dirt
Insulate the outside walls
Then I'd consider just rigid against the joists

Walling off & insulating will help keep the room a lot warmer
The area under the room should stay 50-55 if sealed/insulated correctly
Scuba_Dave is offline   Reply With Quote
Old 06-29-2010, 08:59 PM   #22
Newbie
 
Join Date: Jun 2010
Posts: 26
Rewards Points: 25
Default

Installing insulation under addition.


I would not consider walling in unless you want to trap radon in the enclosed porch. Thats gonna require more design than just the vapour barrier.

Secondly is this space actually heated because if it is not it may be a waste of time?

I would consider looking at your local and national codes to figure out what your minimum r-value is for your floor. Should you choose to do it and wear all the required safety gear to remove the old insulation (see insulation mfgr for details)

As for vapour barrier being the floor. Nope.

I was also thinking about cutting extruded insulation to fit between the joists and strapping the joists. As I put the boards in (2" or more in depth) I would foam them into place (must be snug). and then add exterior grade strapping to ensure they stay tight against the floor. Most extruded insulation have literature on it that say something along the line of acting as a vapour barrier. Foaming them in would seal any cracks. I'd be inclined to stagger/extruded boards and tape the joints untill I reached my desired r value. (this might be a little more labour but it is easier than pouring a slab). Ask a local contractor what he might think of doing? He might just tell you to foam the whole underside.


Just a thought
Bldg 2 Spec is offline   Reply With Quote
Old 06-29-2010, 09:31 PM   #23
Member
 
Join Date: Mar 2010
Location: New York
Posts: 1,763
Rewards Points: 40
Default

Installing insulation under addition.


Gillaustin, do check out that link Gary posted about conditioned crawlspaces. That is how my crawlspace was done and it remains mold free. There are 2 layers of 2 inch OCF foam insulation between the joists with 1x3 boards fastened to the bottom of the joists holding the foam in place. It is all air tight as far as I can tell. Anything that does not seal out the air will allow conduction to take place and condensation will result.
Jim F is offline   Reply With Quote
Old 06-29-2010, 09:35 PM   #24
Newbie
 
Join Date: Jun 2010
Posts: 26
Rewards Points: 25
Default

Installing insulation under addition.


My thoughts exactly.. These rooms are extrmely tough on the home during summer/winter and especially on the mechanical units. They tend to require more energy to maintain temperature balance as they are often an afterthought...
Bldg 2 Spec is offline   Reply With Quote
Old 06-29-2010, 09:40 PM   #25
Member
 
Join Date: Jan 2009
Location: South of Boston, MA
Posts: 17,248
Rewards Points: 2,000
Default

Installing insulation under addition.


Quote:
Originally Posted by Bldg 2 Spec View Post
I would not consider walling in unless you want to trap radon in the enclosed porch. Thats gonna require more design than just the vapour barrier
The proper 6 mil will prevent radon
That would be if any was even present in the ground
Allowing cold air into this area is just going to cool the whole house down

Read thru the link Gary provided:

Quote:
Photograph 5: Conditioned Crawlspace—The way all crawlspaces should look. Dry, warm, part of the house, not part of the outside or part of the ground. Insulated on the perimeter not in the floor. Beautiful.
I'd still insulate the floor
Scuba_Dave is offline   Reply With Quote
Old 06-30-2010, 08:31 AM   #26
Newbie
 
Join Date: Jun 2010
Posts: 12
Rewards Points: 10
Default

Installing insulation under addition.


Should I approach insulating the porch differently where it's open to the outside. Like I said before, the guys at Lowes suggested placing the polystyrene foam over the fiber glass insulation in order to keep the critters out. Can I expect mold to grow on the foam? Would plywould be better in preventing mold? I'm curious since mold grew on the paper backing on the fiberglass insulation that was installed in reverse(this is the stuff that I took down) should I expect it to grow on anything else I use to cover the bottom of the porch?
gillaustin316 is offline   Reply With Quote
Old 06-30-2010, 09:33 AM   #27
Member
 
Join Date: Jan 2009
Location: South of Boston, MA
Posts: 17,248
Rewards Points: 2,000
Default

Installing insulation under addition.


Moisture is coming up thru the soil
Looks like underneath is blocked on 2 sides by house ?
Less ventilation...more moisture
By putting down 6 mil barrier on the dirt you will prevent mosture coming up
You will spend less on rigid closing the area in

If its a moist area under there then almost anything can have mold grow on it
You need to eliminate the moisture
Scuba_Dave is offline   Reply With Quote
Old 06-30-2010, 09:35 AM   #28
Newbie
 
Join Date: Jun 2010
Posts: 12
Rewards Points: 10
Default

Installing insulation under addition.


It's blocked completely by the house on the front. The 2 sides are open completely and the back is partially blocked by the stairs going down into the back yard.
gillaustin316 is offline   Reply With Quote
Old 06-30-2010, 06:30 PM   #29
Member
 
Join Date: Feb 2010
Location: MI's Western UP
Posts: 599
Rewards Points: 500
Default

Installing insulation under addition.


I don't know if you are in a radon area. check that out first

you may want to look at getting some special material they make to close in under mobile homes/
forresth is offline   Reply With Quote
Old 06-30-2010, 07:25 PM   #30
Member
 
Join Date: Mar 2010
Location: New York
Posts: 1,763
Rewards Points: 40
Default

Installing insulation under addition.


I've learned to ask the Lowes and HD reps about their background on the topic they are giving advice on. Some have expertise in plumbing, electric and so on, but many are minimally trained. I've learned to ask this based on a history of getting the wrong advice from the inexperienced ones.

Advertisement

Jim F is offline   Reply With Quote
Reply


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
Basement insulation / vapor barrier questions deepstuff Building & Construction 16 02-09-2012 10:11 AM
How To Install Rigid Foam Insulation on Concrete earthad1 Building & Construction 9 10-26-2010 10:49 AM
Flat Roof and Blown Insulation... inlikeflint Building & Construction 4 01-26-2010 01:42 PM
Insulation over Attic Walkway BigJimmy Building & Construction 4 06-23-2008 03:13 AM
CanLites needed in Insulation addition? i009981 Building & Construction 4 12-13-2007 10:26 PM




Top of Page | View New Posts