Preperation of concrete screed for Porcelain tiles outside

[ReeceT]

Hi,

I am looking for some advice on a couple of questions.

I have set down a concrete screed for the installation of some Porcelain tiles, the screed only went down yesterday so the first question is how long do I need to wait to begin tiling and do I need to do anything else to the screed before I begin tiling?

The tiles I will be using are the Bradstone Mode tiles which are Porcelain. What adhesive would be best to use for this. I have used Mapei Mapeker Rapid Set Tile Adhesive for our indoor Porcelain tiles and it says on the pack it can be used for outdoors also and it is frost resistant. Would this adhesive be good to go outside as it is on offer in wickes for £40 for three bags.

If this is no good then a point in the right direction would be good as I have put so much effort into getting to this stage and don't want it to fall at the final hurdle.

Thanks in advance

Reece

 

[White Room]

The first thing I would be doing is lay some polythene over the screed for 7 days just so it can cure better, this heat will evaporate any moisture you have and could weaken the screed.

 

[Stef]

You can go over it just now with a "Green screed" adhesive, I'm not sure if that addy you have would be suitable with an additive in it.
New concrete I would be wanting a decoupler again not sure for outdoor use but I know you can use Ditra drain as I got recommended it before.

 

[One Day]

Mapeker is utter rubbish. Spend a bit more and get a decent S1 like TileMaster Setaflex.
I wouldn't tile external concrete without (at least) Ditra Drain as Stef mentions.

Do it right - do it once -or save a few quid now and do it again a couple of years later after a good few freeze/thaws!

Balconies: all ground-level assemblies at a glance | Schlüter-Systems - http://www.schluter.co.uk/balconies-all-ground-level-assemblies-at-a-glance.aspx

 

[ReeceT]

Thanks for the above information covered with poly sheet. Will look to use the Ditra Drain and the TileMaster addy. They have a few on their site ranging from the standard that takes 24 hours to the rapid at 3 hours, does it make much difference to the one I use? No one will need to walk on the tiles so 24 hours is not a problem.

Also can I use the ditra drain whilst still green or do I need to wait. Had a look at the website but could not see it.

One further thing, the screed is a little rough in places, it is flat just some bits are a bit crater like (not sure how else to put it), I would assume that these need to be filled before the d drain goes down .

Cheers for the help.

Reece

 

[Kevbos]

I do alot of victorian tiling .on outside paths .firstly which surface is it concrete or screed as they both very different and what thickness .also we use mapei keraquik and seal our screeds with sbr before tiling

 

[ReeceT]

Hi Kevbos,

It is a sand/cement screed about 4:1. The screed thickness is c.60mm.

 

[Kevbos]

If you follow proper drying times you have to wait 1 day for each 1mm in the first 40mm of screed and then 1 day for every 0.5 mm of screed there after .so your looking at 80 days .if you follow the book of drying times

 

[Kevbos]

We use rapid set cement in our path screeds as we have to usually allow access same day for house owners .we tile a week later .as long as screed is dry and not been made wet by weather .we use keraquik and never to date had problems.

 

[widler]

I waited 4.5 years for my outside patio area to dry out , 1mm for every day , then back 5 weeks when we had 5cm of rain , then 1mm for every day, then back another 5 weeks when we had another 5cm of rain and so it went on , it drove my Mrs potty

 

[Kevbos]

Lol .my missus would have found some way to cover it from weather .your lucky she waited

 

[ReeceT]

Well it is covered now and hopefully this will keep it dry.

Not sure which way to go with this now as two differing views.

If I don't use the Ditra Drain, could I use a addy which can go on a green screed. TileMaster Ultimate can go on green and is S2. Would this provide a solution?

Ta

 

[widler]

Lol .my missus would have found some way to cover it from weather .your lucky she waited

I'm joking kevbos , I waited about a month , got that peed off with all the rain I just tiled it

 

[Kevbos]

Best thing choose a tile adhesive supplier ring their technical. They will tell you .I'd go mapei as they always helpful but most big suppliers have a technical side