New DIY tiler introduction Screed issues

[Deleted member 51481]

Hello tilers,

My name is Caley and I thought I would introduce myself to this forum that I stumbled upon having done some preliminary research. I really do the value
forums such as these as they are a fountain of knowledge and truly help inexperienced people such as myself from making mistakes, costly repairs and avoiding getting ripped off by nefarious characters.

I have just project managed two single storey extensions having only ever dabbled in light DIY and I've made a a few errors along the way but nothing insurmountable.

My current project is to lay a new floor in a kitchen diner, we're at 2nd fix stage so it wont be long until its flooring time!

One of the errors that I made was allowing the groundworker to take the floor levels off the wrong DPC so I have a new concrete base that is 40mm lower than that the existing floor make up of the house.

This has caused me a few nights of restlessness and I've been looking at various flooring options such as engineered wood and porcelain tiles and we have settled on the latter. My main concern is how to increase the floor height by 25-30mm in addition to the 10mm tile. The options I've looked at are screeds, self levelling compounds and thick bed adhesives and ultimately I'm looking at the pros and cons for these three options.

So that's where I'm at the moment and would welcome any advice at this stage.

Cheers
Caley

 

[Waluigi]

XPS tile backer board

Welcome !

 

[Qwerty]

Welcome to the forum

 

[GoneGuy]

Hello and welcome

 

[Time's Ran Out]

Welcome - as above you can use tile backer boards to build up to your required heights. Available in all thicknesses.
WORD FOR TODAY.
Nefarious - Wicked or morally bad.

 

[Flintstone]

Welcome, as above, a backer board is the best option here available in 20 or 30mm

 

[Albert]

Welcome, as above backer board

 

[Blunt Tool]

Welcome as above backer board, personally I would use foam backer boards Schlüter, Wedi, Jackoboard, Marmox etc as it’s another layer of insulation
My word is facetious meaning treating serious issues with deliberately inappropriate humour

 

[Deleted member 51481]

Thanks for the warm welcome and the advice. I wasn't even aware of backer boards yet they sound like a good alternative and a cost effective solution!

My initial question would be what if you need to achieve different height thresholds to match the existing internal floor in the existing house (40mm from concrete slab) and external bifolds door cill which ranges from 15mm to 25mm across the width of the doors which span 4 metres ?

 

[Old Mod]

Hi and welcome to the forum Caley.

 

[Old Mod]

If I’m reading this correct I’d say you’ve a job on your hands.
Are you Tiling existing areas?
It’s your slab that’s out of level to the Bi-folds I assume?
The doors are level but low, is that correct.

 

[Old Mod]

Some images of the new and existing areas and bi-folds would help I’d expect.
Preferably wide angled so that the areas can be put in to perspective.

 

[Deleted member 51481]

Here you go chaps

 

[WetSaw]

What's the distance from the doors to the original floor?

 

[Deleted member 51481]

5 meters pal.

 

[WetSaw]

40mm where the new meets the old and 25mm max at the doors. 15mm at the doors doesn't give you much to play with once you have 10mm tile plus adhesive so you'll need to be careful. I think you'd lose the other 15mm over a 5m span without noticing.

 

[Deleted member 51481]

Thanks but how do I create the 20mm fall needed between the existing floor and new bifold door cills with backer boards please?

 

[Spare Tool]

You'll have to use a combination of backer boards and slc. Use 10mm boards (doubled up if necessary) to take the bulk of the discrepancy out then leveler on top.

 

[Deleted member 51481]

Okay, are you aware of any foam boards that increase in thickness in smaller increments than 10mm please

 

[Old Mod]

Yes, there are wedgeboards available that start at 10 and rise to 20m.

 

[Albert]

Okay, are you aware of any foam boards that increase in thickness in smaller increments than 10mm please

Yes you can get 6mm and 4mm

 

[Old Mod]

wedge boards

 

[Old Mod]

Using a combination of flat and wedge boards you can pretty much cope with any slope.

 

[Deleted member 51481]

Thanks, they're not cheap though at £150 per sheet 1200mm x 1200mm. I don't need waterproof versions so are there cheaper alternatives please as had a search and can't locate anything similar?

 

[Dumbo]

Thanks, they're not cheap though at £150 per sheet 1200mm x 1200mm. I don't need waterproof versions so are there cheaper alternatives please as had a search and can't locate anything similar?

Who is going to do this work for you or are you doing yourself . Because you need somebody that can think laterally and has a decent skill set to get what you want to achieve and for it to look good .

 

[Deleted member 51481]

To be honest I was hoping to do it myself if it was straight forward and level but open to advice if you think it will be a nightmare having to deal with the levels.

 

[Deleted member 51481]

Incidently the tiles are quite large 800mm x 400mm so I would imagine they're not as forgiving as smaller tiles.

 

[Dumbo]

Incidently the tiles are quite large 800mm x 400mm so I would imagine they're not as forgiving as smaller tiles.

To be honest although there are some tiling gods on here that deal extra large format on a daily basis 800 x400 is still a large tile for a lot of people . Personally I think you may struggle but I don't know how useful you are at taking advice and transferring that to what you are doing .

 

[Deleted member 51481]

With the right advice and preparation I'm fairly confident I can achieve an acceptable finish that will last. It may not be perfect but as long as it's done properly then I would be satisfied.

 

[WetSaw]

The problem you have is getting the floor flat ( not level ). You'll need to be meticulous in the subfloor preparation and as you have various differing levels to begin with it won't be easy and with only 15mm at the doors you can't afford to make any mistakes. With that size tile you want to get it as flat as possible.