Raising a cement floor combined with chipboard

[Laurens]

This weekend I removed the kitchen and exposed the floor, there was chipboard under the fake plastic tiles. I was hoping to be able to lay plywood but the chipboard was rotten all over the place so I removed it.

90% of the floor is open and is cement but on the right side of the kitchen there is still around 10cm of chipboard.See the following picture of the situation before I removed everything:

As you can see there is a strip of chipboard on the right side. This chipboard is not rotten and the quality seems to be a lot better then the stuff I removed, I cannot remove this as it is supporting the wall. The rest of the chipboard is removed and the difference between the remaining chipboard and the cement is 4cm. The cement did dry fairly quick so I dont think there is moisture coming from below.

So the big question is how do I raise the floor with 4cm? Cement is not really an option as it takes to long to dry and my girlfriend is not a big fan of putting wood again. So I was advised to put 30mm SLC and then 10CM Warmup Insulation Board (so that the floor is not that cold). This will bring it to the same level as the remaining chipboard so I can tile the floor. The tiles on the chipboard wont be visible as there will be kitchen cabinets.

The cost for this is 245,- when buying from Topps Tiles. Is this a good idea or should I go for another option?

 

[Gazzer]

Why not just 40mm Marmox boards ? Cut the remaining 10cm of board away with a circular saw.

 

[Laurens]

Have been reading about this and it does sound very good and it is cheaper that the option advised by Topps Tiles.

A few questions:
1. Does the floor to be levelled? The floor is level but there are some round spots of 3cm where the cement is a ~5m higher.
2. If I understand it correct I tile this onto the floor, bind the boards with Marmox tape and then tile on it?
3. Their specification says that the floor tile should be at least 50x50, the tile I have is 45x45 I assume it is ok?

I wont do the final tile myself but I need to have the surface prepared.

The quality of the Marmox boards and the fact you can simply cut it almost sounds to good to be true.

Another small question, on the picture you can see the wall and the brown paper. On this brown paper there where tiles, what would be the best preparation be to re-tile?

 

[Gazzer]

50 mm ????? Not sure what you mean
Are you confusing mm with cm

 

[Laurens]

Silly me

 

[Gazzer]

Ok so you are using 450mm tiles. so you have no issue with Marmox.

You have 2 options to prepare the floor before marmox.
1, remove high spots with grinder or rubbing stone.
2,apply self leveller before the marmox.

 

[Laurens]

Ok so you are using 450mm tiles. so you have no issue with Marmox.

You have 2 options to prepare the floor before marmox.
1, remove high spots with grinder or rubbing stone.
2,apply self leveller before the marmox.

Thank you so much Sir Ramic.

So I have the following items on the list:
8x Marmox Board 30mm (1250 x 600mm) - about £100.
3x Bal Multibase Grey 25kg - Self levelling compound - about £83.

I will get the adhansive from B&Q and I am thinking about Mapei as that is recommended on quite a few sites. They also have Unibond but I cant find much about that.

 

[Gazzer]

I would stay clear of Unibond ...just my opinion.
You would probably be better buying adhesives from a tile shop. Tile Giant, Tile Choice CTD etc
For Self leveller I can recommend Mapei Renovation screed, Ultra Level it One and Weber flex all good brands and great prices.
Knowing where about you are in the UK helps as someone may be able to point you in the right direction.

 

[Laurens]

Ok good to know, I will stay away from Unibond then. B&Q has also Mapei and I will use that for both the adhesive and grout.

I am living in New Cross, London. There is a Topps Tiles and a Tile Giant around the place I live so I will get the Ultra Level it One from Topps Tiles. One bag covers 5m² at 3mm so I will get 3 of those bags to get 9mm and then 30mm Marmox boards. With the adhesive between the SLC and the Marmox I should get close enough to the 40mm.