Does concrete bond to itself? Making concrete a step?

[devs]

Hi guys simply question really but wasn't sure of the answer.

I've got to create a concrete step prior to a tiler coming to tile. Its from one (underfloor heated) internal concrete screed floor to another.Will the two surfaces bond or do they even need too? Also the step will be from the side of the wall. Do I just create an L shaped wooden frame a hold in place until it goes off?

Any tips that you could share as I've never done this before..

Many thanks,

Devs.

 

[r896neo]

How soon are you getting it tiled? If you pour a concrete slab like that you wont be able to tile it for a few weeks as it will contract a little as it cures and could pop your tiles.

If it needs to be done soon then you could simply lay a concrete block or two? You could tile that the following day.

If you do pour it try to rough up the bottom step and apply some pva cement slurry before you pour it for good measure. In reality it doesnt matter assuming your step will be more than 75mm thick.

 

[^woody^]

Consider making the step from something else - concrete blocks or lintels.

Or a timber frame clad with cement board.

 

[devs]

Thanks a lot guys I wouldn't have the time to allow for the concrete to cure (didn't consider that!) so will have to take the block route. This could be interesting as I've never laid blocks before. Trust its a case of mixing the sand and cement bedding them and and watching the level?

 

[^woody^]

Yes that's it.

Brush all dust off the floor, dampen the surface, and use a strong 3:1 mix using building sand. Use dense concrete blocks 7N.

Tap the blocks and give then a slight twist to form a strong bond.

The only issue you might have is the required height of the step. Is it higher than 110mm?

 

[devs]

Woody many thanks for all the help, really helpful!!

The step will be 150mm will this cause me issues

 

[^woody^]

You can get 140mm concrete blocks to lay flat.

Otherwise a 100mm block and cut 35mm paving slab.

 

[devs]

Okay thanks woody I'll see if I can get some 140s and take it from there. Cheers!