yet another building question

[Norman Verona]

The porch is now sealed, has windows and doors but will not be finished until October/November.

The floor is concrete.

Can I seal it (to stop the dust) with a coat of PVA? The tiles that will be going down are hand made clay (called Tomatz) with sand/cement.

IF it's OK, what's the mix,

Many thanks.

[ajpearson]

From personal experience if you are going to tile i would not, as you are not likely to get the tile to have sufficient grip on the adhesive to ensure a grip

[Norman Verona]

Morning AJ. That's what I was afraid of. The reason I had so much trouble with the other tiles was because they had been coated with Linseed oil.

However, when I asked if I should PVA a plaster boarded wall before sticking the wall tiles on I got a mixed response, some said YES and others said "if you want, but it doesn't do anything"

I'll vacuum the dust up today and see if it comes back (I'm sure it will)

The tiles will probably go down on a sand/cement base,not tile adhesive. They are about 2 cm thick.

[ajpearson]

I am sure somebody with some more experience will be along soon, I know I tried it in my utility room and when I get around to tiling it was crap.  Ended up ripping the tiles up, and stipping back the PVA coat

[Norman Verona]

I'm not doubting you, only these tiles are different to normal house tiles. They are hand made clay tiles, at least 100 years old and will be laid on a bed of sand and cement. In fact they came out of the hay loft upstairs and there they were set in a mixture of earth, horsehair and poo.

I suppose the question could be "will sand a cement mix bond to a PVA'd concrete base"

[Terry Everall]

i would not ova the concrete

a sand cement screed will bond to the concrete as it has the same material content 

[ajpearson]

Why can't you get the tiles down earlier to avoid the constant dust build up

[Norman Verona]

It's not to bond but to seal it as the tiles will not be laid until October at the earliest.

How can I seal it to stop the dust, until the tiles are laid?

Thanks.

[ajpearson]

Go rustic, and put a lywer of straw down

[Norman Verona]

It fills up with that quickly enough anyway.

 

It's much better now I've cleaned up the front, but still walking in grass, stones and crud.

 

OK, back to clearing up.

[robsurplice]

you need proper tile adesive you mix it useing drill with mixing tool or buy ready mixed sand and cement no good and you need tile float ie grooved

[KugaWestie]

Why dont you coat it with a layer of Blackjack (liquid damp proof membrane)

 

That would seal it, help with damproofing and a cement/sand screed will bond to it no problem.

 

See here http://www.riw.co.uk/Products/DPM.aspx

[Mark (smokey mow)]

Hoover up the dust that's there no and then lay a square of cheep lino over the top of it till you're ready to tile it.

[Rory's Dad]

Old farts way (cheap):

 

I'm assuming their is some damp proofing under the slab  . 

Brush the floor

Slop on some water with pva added

Mix up some sand and cement - 4 or 5 : 1

Some pva added to the sand and cement will help plasticise the mix and make it more adhesive

The mortar bed needs to be 5mm thick at least (I'm guessing the tiles are not of a constant thickness)

Wet the tiles before you lay them

Don't let it dry too quickly - an old wet sheet over the top once the tiles are laid should do the job

 

...or you could get some expensive tile cement from a builders' merchant and follow the instructions  

 

Good luck - Rory's Dad

[jim_l]

Norman, PVA is a bonding agent, often specified and used to bond concrete to, for example, a cement screed.   I have used PVA prior to tiling both floors and walls, and can't see how it would cause a problem.  One thing is for sure, your tile cement won't bond to a dusty floor.

 

The concrete needs to have cured, and ideally not be too smooth, a mechanical key helps. Use 1 or two coats at 5 parts water to 1 part PVA.

 

  Jim