Hi, Sorry if this is the wrong forum to post in. I didn't know where else to put it. I recently had a garage built and there seems to be a bit of a void in the slab on the low side (between the bottom of the slab and the grass/ground) as shown in the photo. Is this a problem? Is there anything I can/should do about it? http://i142.photobucket.com/albums/r...L/DSC00948.jpg (http://i142.photobucket.com/albums/r87/LOACH_PAUL/DSC00948.jpg)

Pack with sand

did u dig into the ground or jus put the boxing above ground?

Quote: Originally Posted by mulkers [View Post] Pack with sand being summer...the ground is dry.. thats why u hav the gap. fill it it with gravel or sand.

Thanks guys most appreciated. I had the slab laid while overseas. I got it done in winter because I read that it was better due to a slower dry time and therefore less chance of cracks. I didnt realise that a big gap would appear like that in summer.

who ever has done it jus formed the slab above ground. should have been dug about 150mm and then crushed rock compacted. sand will do little if nothing now.

The slab looks pretty thick on that side 150mm? Should be fine if your really concerned about it just get some rapid set and slap it in there having no gutters doesn't help either as every time it rains it will wash dirt away from the slab

Put crushed rock down. Sand will just wash away when it rains.

Shoving crushed rock or DGB in there now will do nothing. Subgrade should have been suffiently based and compacted before hand. With a slab that thick and assuming theres sufficient steel in there it should be fine. You could probably throw some rapid set in there to neaten it up a bit and fill the void i guess.

Thanks again for the replies guys, will see what I can do about tidying it up.

I should have been clearer. I'd put an edging along there with crushed rock, or even a garden bed. It wont fix the problem but it will neaten the appearance.

put a cement mower strip around it, dig some ground out, put some gravel down and pack it down well before putting your box section up

Is there any FCR under that slab? It doesn't look like there is which is a big no no. Although the nice thick slab should stop it cracking(providing the right mesh was used). However it wont stop the slab from moving around. Probably not a huge drama but far from ideal if you paid big money for it. If it does move, grab a post hole digger and bore down on each corner until you hit something solid and mesh/concrete it - basicall underpinning it. It would obviously be best to consult an engineer also.

They should've dug into the ground more & used packing sand. Also they should've reinforced the sides with a thicker concrete wall/barrier.