Extending concrete floor

[howy1]

Hello all , i wish to extend my dining room floor by 75mm it is a roughish concrete edge that drops down 50 mm to another room , so effectively i have a infill of 75mm wide x 50mm deep x 2m long how best can i do this ? i thought about putting a temporary piece of 50 mm timber down for the height then unibond the gap and fill with cement and sand , what mix would be best and will it all adhere to exsisting surfaces , cheers

 

[howy1]

Just a short reply will do not rude .

 

[roughcaster]

If you can, why not drill a load of holes (couple of dozen or more) along the 2 metre length, put in raw plugs and 60mm/65mm screws, leaving the screws sticking out by half their length. Just before you fill up the gap with sand and cement, uni bond the edge, fill it up, giving it a good tamp down as you go, and the screws and uni bond will hold the new extended 75mm no problem. Make sure the screws are well staggered. Dont drill the holes to near the top, and for the top ones,I would drill them at a "slight" angle downwards. Your idea for the temporary 50mm piece of timber will work fine, just remember to put something weighty in front of it to stop it from moving about. Leave it for a few days to harden, and that's it.

Roughcaster.

 

[howy1]

Many thanks roughcaster , what a good idea its nice to have something to work with i will do the screw idea cheers

 

[roughcaster]

Howey1,
I forgot to mention the mix, 3 parts concrete sand ( rough gritty sand) to 1 part portland cement. Nothing else mixed in it, only water, added slowly. Don't make it overwet, but wet enough to be tamped down to grip onto the screws.

Roughcaster.