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

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

Reply
 
Thread Tools Search this Thread Display Modes
Old 04-24-2010, 10:39 AM   #1
Member
 
Join Date: Oct 2009
Location: Indiana, PA
Posts: 1,304
Rewards Points: 506
Default

Gap between slab and wall


I am in the process of preparing to finish a space in the basment... along with sealing off the rim joists from the outside, I was looking at the floor... I noticed the poured slab as about a 1/4" gap along the wall the slab never seems to touch the cinder block wall... Is this from shrinkage? i dont think its french drains because wouldn't that be larger then a fourth an inch?... can this be sealed up? I think bugs are crawling though it... or at least down into it to hide... if it can be sealed... can you just use silicon caulk? or what would be best? thanks

BlueBSH is offline   Reply With Quote
Old 04-24-2010, 12:04 PM   #2
Civil Engineer
 
Join Date: Mar 2009
Location: Boston
Posts: 4,252
Rewards Points: 2,082
Default

Gap between slab and wall


The gap is almost certainly unrelated to a French drain, as you noted it is too narrow. It is almost certainly not from shrinkage, shrinkage typically produces hairline cracks, not a straight line, and certainly not immediately adjacent to the block. The gap is most probably there as a crack control joint, and may not extend all the way through the concrete. Check it with a probe, a coat hanger would work well.

If the joint does not extend full depth, bugs are probably not crawling through it, and you can leave it alone. If it does extend full depth, and you wish to caulk it, make sure you use a flexible caulking like silicone, since the width of the joint probably varies seasonally, and you don't want to damage either the caulk or the concrete as the joint moves.

Daniel Holzman is offline   Reply With Quote
Old 04-24-2010, 03:38 PM   #3
Member
 
Join Date: Oct 2009
Location: Indiana, PA
Posts: 1,304
Rewards Points: 506
Default

Gap between slab and wall


I tried to push a 12 gauge ground wire down into the crack and I can push it almost 7 inches deep before it stops and pulling it up it has some dirt on the end... must go all the way down
BlueBSH is offline   Reply With Quote
Old 04-24-2010, 07:37 PM   #4
Mod
 
kwikfishron's Avatar
 
Join Date: Mar 2010
Location: Kansas (NCK)
Posts: 7,581
Rewards Points: 2,194
Default

Gap between slab and wall


If your poking down to dirt then yes the bugs can get in through. Don’t try to fill the entire 7" gap with caulk. Stuff a backing down there first. You can get ’ to ” round foam backer at any good hardware store, comes in a package 20-25’. Stuff that down there so all your caulking is a ” x ” gap. I’d use a polyurethane caulk like Vulkem or Quad, they will stick to concrete way better than silicone.
__________________
A Picture Is Worth A Thousand Words
Especially In The DIY Chatroom
kwikfishron is offline   Reply With Quote
Old 04-25-2010, 06:31 AM   #5
Member
 
Join Date: Jun 2009
Location: atl & hilton head
Posts: 3,287
Rewards Points: 2,156
Default

Gap between slab and wall


its a version of a ' slot drain ' & was formed when someone plac'd the floor then ' pull'd ' the ( form/foam/board/isolation jnt) which had been placed against the wall,,, in theory, any infiltrating water from the wall's supposed to enter that slot & drain out below floor,,, never saw it work like that, tho.

backer rod & sealant ( silicone-polysulfide-polyurethane ) [ NO CAULK! ] as suggested.

in theory, there's no difference 'tween theory & practice,,, in practice, there is !
stadry is offline   Reply With Quote
Reply

Tags
slab


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
Need advice on pouring slab inside existing wall. bmwbykrydr Building & Construction 2 04-05-2010 10:11 AM
Concrete slab to foundation work tntgarv Building & Construction 3 02-28-2010 12:23 PM
Correcting exterior wall build on slab KAdams4458 Building & Construction 12 08-23-2009 01:30 AM
Brick wall - concrete slab floor separation. DewmanTN General DIY Discussions 5 07-24-2009 09:57 PM
Help! Tile-over-concrete slab problems jeffchri Tiling, ceramics, marble 6 12-24-2008 05:22 PM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.