basement/crawlspace issue - Contractor Talk - Professional Construction and Remodeling Forum

formula11e · 10-01-2008, 05:14 AM

Should this be sealed up where the joists for my addition sit the foundation?There is a crawl space under the addition.The only thing blocking the out side air from coming in to the basement is the insulation under the crawl space I bought the house last year and last winter first foor floor and basement was allways cold and (damp all the time). Also If I was going to put insulation up under the 1st floor do I have to put some kind of plastic barrier since the floor has planking and not a plywood sub floor?

rotarex · 10-01-2008, 06:39 AM

you gotta put your vapor barrier on top your joist or wood floor then cover it with what ever you want, and to hold up the insulation from falling down a breathable membrane

neolitic · 10-01-2008, 06:45 AM

No idea where you are,
if you are in my climate,
there is just so much wrong there.

formula11e · 10-01-2008, 05:09 PM

Im in northern NJ sussex county what is the wrong part the crawl space pic or the basement wall pick?

neolitic · 10-01-2008, 05:31 PM

Straw and cardboard don't make
a very good crawl floor.
The intelligent thing to do is
put a vapor barrier on the
ground and up the walls,
insulate the perimeter
(walls and joist pockets),
pull that crap out of the
floor system, and treat it
as the conditioned space
that it should be.

Do some homework.
BuildingScience.com
Google
Local building code........

formula11e · 10-01-2008, 05:54 PM

The people that owned the house before me had goats and thats where they kept the straw I was planning on taking that crap out this weekend anyway.There is thick black plastic over the dirt in the crawl space.What about the shared wall where the basement/crawl space meet?

neolitic · 10-01-2008, 06:08 PM

If it's all conditioned space,
it's all conditioned space.
What do you do between
the living room and the
dining room?

CO2Solutions · 10-01-2008, 10:06 PM

agree with Neo...I can't tell you how many mould remediation jobs I do in crawl spaces that aren't properly completed...not to mention the potential damage moisture can do joists, hardwood flooring etc.

Blockade · 11-02-2008, 01:40 PM

Reading the other postings, I too would remove the insulation from the joist spaces and insulate and put vapour barrier on the exterior foundation wall. Putting a vapour barrier on the ground will help with unwanted moisture not to mention your home may be exposed to Radon gases. And it would do no harm to put rigid insulation of the ground either.

**genecarp** · 11-02-2008, 03:14 PM

Rip the whole house down and start again, new plans, build to local codes (just kidding). Start with that crawlspace floor, clean it out, put down a vapor barrier, and pour a rat slab. thats step 1.

Home Serve · 11-02-2008, 04:23 PM

Quote:

pour a rat slab

Rat slab? haven't heard of that around here in Midwest.
What is a rat slab?

Blockade · 11-02-2008, 04:35 PM

It is very common in our area to just put R8 insulation on the inside of the foundation with a VB and put a 6ml barrier down on the ground, covered in sand. This will allow rodents and insects to move from inside to the outside with little effort.
A rat slab is not a bad term. In Southern Alberta it may be called a Ratter slab.
Moles and gophers if you live in Saskabush….

**genecarp** · 11-02-2008, 08:24 PM

Quote:

Originally Posted by Blockade

It is very common in our area to just put R8 insulation on the inside of the foundation with a VB and put a 6ml barrier down on the ground, covered in sand. This will allow rodents and insects to move from inside to the outside with little effort.
A rat slab is not a bad term. In Southern Alberta it may be called a Ratter slab.
Moles and gophers if you live in Saskabush….

Different terms depending on geographics, for us in the northeast a rat slab refers to 3'' or so of concrete poured on the floor of the crawlspace. typical here 6ml VB, FOLLOWED BY some wire and a few inches of concrete roughly troweled out. basically it addresses moisture issues, gives all the trades a neat clean place to crawl around, and when we are done, the homeowner has a nice dry/ clean space for storing there christmas tree and luggage. G

neolitic · 11-02-2008, 09:32 PM

Quote:

Originally Posted by genecarp

Different terms depending on geographics, for us in the northeast a rat slab refers to 3'' or so of concrete poured on the floor of the crawlspace. typical here 6ml VB, FOLLOWED BY some wire and a few inches of concrete roughly troweled out. basically it addresses moisture issues, gives all the trades a neat clean place to crawl around, and when we are done, the homeowner has a nice dry/ clean space for storing there christmas tree and luggage. G

Rare as rabbit antlers here.

Dan13 · 11-04-2008, 09:52 PM

You should pull out what you have level the floor if its not already, put down a vapor barrier on the floor and run it up the walls about a 1ft. and then get someone in there to spray foam the surrounding walls and call it good. This will give you a nice dry & warm crawl space for many years to come. If and when you can afford it you can always pour a slab should you feel you need one, but pea gravel over the vapor barrier works nice to.

sawyerEd · 12-16-2008, 01:11 PM

yikes, I can already see condensation on your floor joists. Your new addition is rotting before your eyes. You've been told, now get to work. Remember vapor retardent layer against masonry. vapor barrier on the ground. Having a cold wet crawlspace or basement under a house is unacceptable. Sorry.

mics_54 · 12-16-2008, 02:04 PM

vapor barrier on the ground sealed at the joints and edges. spray foam the rims. provide some air circulation. lose the floor insulation. Insulate the crawlspace walls with 2" ridgid foam (check local codes for fire proofing requirements on the foam))