Help after attempted levelling floor

[Steve89]

Hi all,

Really need some advice please, I am currently trying to redo my downstairs toilet. This time I have decided to try and do some of the work myself and some with professionals.

I was going to have a go at the painting and tiling myself but have got a plumber in to do all the pipework. As these are big tiles 600 x 600 and there are only a few to put down I decided to give it a go.

Anyway, the concrete floor seemed fairly level, I have cut all the tiles to size and was ready to start laying them when I had a change of mind and decided the floor wasn't level enough. Poor planning I know. I used some cement based leveller from screwfix designed for 0-10mm as the floor wasn't to bad. It did set quicker then I thought, at a glance it appeared very flat but when putting a tile or straight edge down it is obvious there are some lower spots by the walls, I had another go with levelling compound to try and address the issues after reading the forum. You can see in the pictures the darker spots where I have tried to raise the level. This has made it better but there are lips where it joins the first batch I put down. Long story short when I lay the tiles there is a bit of rock on some of them and a lip of around 2-3mm between a couple of the tiles. I assume there will also be small gaps underneath bits of the tiles. I know there is lots of advice onlineView media item 70455 but are any of the below an option? I don't want to make it any higher ideally so don't want to screed again.

Would a thick layer of tile adhesive take up the gaps?
Can I chisel it out and go again?
Would a concrete floor grinder help?
Should I give up and get someone in to fix my mess? If so is this a quick job? Only reason I ask is that it's been nightmare trying to get people in at the moment as everyone seems booked up for weeks.

Thanks all

 

[Swwils]

How far out is it?

+-3mm over 2m will be done to tile onto, essentially you should end up with no gap greater than 6 mm on straightedge.

If the floor is flat but sloped then you have a different issue.

 

[Steve89]

Hi,

Thanks very much for your reply, the floor isn't sloped overall as you can see on the spirit level. There are just high and low spots which you can see in the second picture. You can also see where I have tried to raise the level in places but not done a great job feathering it into the first layer of screed leaving 2-3mm drops. It is better then it was with the second going over as there were some quite low spots, except now I have the rough joins.

One end of the room is fine but there one bit in particular at the photo end where the tiles have about a 3mm lip when I lay them down & a bit of rocking. I do have some of the below cement so wondered if I could mix some and try and neaten it but worried I would make it worse to be honest.

https://www.screwfix.com/p/no-nonse...PpYvKpzdNGQVbHIbGakaAlq9EALw_wcB&gclsrc=aw.ds

 

[Swwils]

Good preparation makes the tiling alot easier.

The tiles won't be resting on the floor dry, trust the level and you are saying you are not more than 3mm out, so it can be accommodated in the tile adhesive.

Make sure you use a self leveling system, it makes it very easy.

Correct bed depth and coverage is what makes it all work.

 

[Steve89]

Good preparation makes the tiling alot easier.

The tiles won't be resting on the floor dry, trust the level and you are saying you are not more than 3mm out, so it can be accommodated in the tile adhesive.

Make sure you use a self leveling system, it makes it very easy.

Correct bed depth and coverage is what makes it all work.

Thank you Swwils, really appreciate the quick response. Would a decent sander smooth the rough bits or am i wasting my time? I guess even if I smooth them the overall drop will still be the same.

Apologies but one final question, I was going to use a 10mm trowel, is it worth going bigger to give more play or is 10mm OK? Also have I understood right that a 10mm will give roughly 5mm of adhesive depth? If I go much bigger I might have to take a tad more of the door architrave.

Cheers

 

[Swwils]

Trowel selection is based entirely on what gives you the correct coverage for the tile. The best thing to do is to lay one then pull it up and check the coverage obtained.

As a general rule of thumb:

• Mosaics/ small format tiles - 3-4.5mm
• Small/medium format tiles - 6mm.
• Large format tiles - 8mm.

Square-notched trowel ridges tend to collapse over on each side when you embed the tile into the bed. Pushing the tile down into the bed of square ridges causes the ridges to fold over from the top of the ridge, then spread out.

U-shaped ridge spreads OUT when embedding a tile into the bed. Pushing a tile into the bed of rounded ridges causes the ridge of adhesive to spread out, from the bottom, with less possibility of trapping air.

Always sort the prep first, do not be tempted to lay a overly thick bed to "fix" a floor.

 

[ETAF]

Son-in-law had a similar issue with concrete that had been laid and a screwfix latex Self levelling screed https://www.screwfix.com/p/mapei-ul...XUlaFp3c0EwET5bo700aAhdLEALw_wcB&gclsrc=aw.ds.

he used a grinder to remove a few of the high sections and make it perfect - but a lot of work. Not sure what disk he used , but i think it was something like this one
https://www.screwfix.com/p/segmented-diamond-grinding-cup-125-x-22-2mm/4108v

created a lot of dust

 

[RandomGrinch]

Hi,

I don't know if you picked up on this from @Swwils :

Make sure you use a self leveling system, it makes it very easy

A tile levelling kit, such as this:
https://www.screwfix.com/p/vitrex-lash-tile-levelling-system-spacer-clips-100-pack/3191f
Is so useful for a DIY'er; especially to avoid lippage with large format tiles.

 

[Mr Chibs]

I used the vitrex system for the first time when laying my floor. I wouldnt lay a floor without them now.

 

[Steve89]

Thanks everyone, I did see about the tile levelling but appreciate the reminder. I have bought some of the wedges they sell in Topps Tiles, I have also bought a disc similar to the one you have linked ETAF so thanks. Will give it a go tonight or tomorrow to get rid of a few of the more rough spots. Not looking forward to the dust but never mind...