Screeding garage base?

[Harry Bloomfield]

Just a possible future project at the moment...

I'm considering both improving the flatness and increasing the floor level of my garage by screeding it. It is a little uneven due to the fact that I very slightly underestimated the quantity of concrete needed, when I originally laid it many years ago - which left it a little rough finished at one end.

It could also do with the original floor level to be increased by about

1/2", to improve its resistance to flooding. The later due to a clay sub soil holding water in extremely heavy periods of rainfall. There was just a slight ingress a few weeks ago, which I would like to resolve.

The floor area is 24' x 12'. I have seen screeding laid on top of concrete to produce a good smooth finish, but how thin could this be laid? How do you make a screed mix? Once dry, would it be waterproof on might it allow moisture to track through it?

Any other ideas what to use instead? The finish will have to be fairly rugged, able to cope with the weight of cars and their maintenance/repairs.

Thanks for any replies.

[Weatherlawyer]

Floor screeds are about an inch thick. Why not run it an inch to 2 inches at the back so that any water flows straight out?

Make it about six to one very coarse sand and cement. Wet the floor and lay it on tilt fillets or raised batons. When you finish a section remove the fillet and fill in the space.

When it is hard enough to walk on (maybe 6 hours or more, maybe with a ply sheet under you) go over it with your steel trowel to polish it. It brings the cement up to the surface and seals it.

You will need something at the edge to take the shock as the car hits the floor. A strip of triangular section will do.

Google is playing up again maybe causing double posts. If it irks, tell the buggers.

[Tony Bryer]

IME the usual spec for screed is 1:3, 50mm thick. I doubt whether 1:6 with a car being driven over it would last.

[Phil L]

It would last..about 15 minutes!

[Phil L]

Screed needs to be a minimum of about 40mm, anything less and it will crack...the best thing for screed in a garage is granno (blue grit, very coarse) mixed 3 parts to one part cement, although if you are putting it thin, make it 1:1.

Prior to this you will need to make sure the floor is spotlessly clean and apply neat unibond (PVA), screed while wet - you'd be wise to do it in sections and have it sloping towards the door, where the granno feathers out to nothing it's as rough as a bears arse, here you'll have to use sand/cement mixed at 1.5 sand to 1 cement and again laid on wet pva.

[Stuart Noble]

The proprietary brands of flooring screed can all be used in much thinner layers. Certainly the latex type can be feathered down to virtually nothing without cracking

the best thing for screed in a garage is granno (blue grit, very

[Phil L]

They aren't screeds as such, they are levelling compounds, and you've hit the nail on the head as to why they don't crack, they're flexible with the latex in 'em. As an aside, the term 'levelling compound' is a misnomer, they don't level any easier than anything else, they smooth out easier but it's not neccesarilly level.