The right sand

Jun 08, 2013 9 Replies

I am about to lay slate tiles on top of an existing concrete slab. I was wondering what sand to use to bed them in. I would normally use plastering sand but I was wondering whether sharp sand would bind them better.



I also planned to use a 4:1 mix, is this right?



Informed opinion would be very helpful.



thanks



Jonathan


Don't use cement. Get the proper adhesive or they will come loose very quickly. It is quite expensive.

ISTR cement fillets stick well enough to slate roof tiles

snips

On a stable bed like a concrete slab, cement/sand should do nicely. On something less stable like slabs on sand, maybe not.

NT

On Saturday 08 June 2013 17:50 Phil L wrote in uk.d-i-y:

+1

Mortar beds are old skool.

A powder (ie mix as required) cement based adhesive is far superior.

Look at Mapei, BAL and others - there are a wide range from slow set, fast set (lay in 30 mins, walkable the same day), extra water resistant and so on.

The way a pro did my slate was:

1) Draw 2 guide lines at 90 degrees to follow (taking account of non parallel walls and to avoid having to lay a thin strip down one wall.

2) Loose lay a few rows and cut the edge tiles.

3) Mix adhesive and lift and stick a few tiles at a time.

4) Continue until room done.

5) Apply tile sealant

6) Grout (step 5 makes it easier to sponge)

7) More sealant and/or colour enhancer.

On Saturday 08 June 2013 20:25 snipped-for-privacy@care2.com wrote in uk.d-i-y:

Yebbut just because you can doesn;t mean you should.

They used mortar in the old days because they had nothing else.

These days, adhesives are far superior, faster, more reliable and easier.

They certainly have some advantages, but from the various modern versus vic torian tiling jobs I've seen it seems modern adhesives arent as reliable. A flat concrete floor slab gains the least from modern tile cements. And wit h a given budget you get nicer tiles using cement :)

NT

OK my fault, I should have said this is outside, does that change things?

Jonathan

On Sunday 09 June 2013 11:40 Jonathan wrote in uk.d-i-y:

You can get exterior grade adhesives (powder, cemment based). Probably overlaps the subset that are rated for wetrooms.

The ones that would not be suitable would be the ready mixed ones.

..doesn't know what the left sand is doing?

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