Hi All I recently had an oak floor installed in my Edwardian terraced house throughout the downstairs hallway and living areas. Prior to the joiner laying the floor (with sikabond T54 adhesive), the builder laid a self levelling screed over the existing quarry/mosaic tiles in the hallway and living room. The floor failed spectacularly shortly after, expanding and buckling due to the moisture coming through the screed from the tiles underneath (no damp proofing installed at any stage). Setting the subsequent arguments and ensuing legal battle to one side (damages run into the thousands), I'm scratching my head about what to do next now I've ripped most of it up. The floor was also laid in the front reception room which was already concreted with a DPM so it's been fine, I'd therefor like to re-do the oak floor in the quarry tiled living room at least (possibly have some kind of tiles for the hallway though). I should add the existing tiles are all too far gone with various sections vandalised by previous owners! I'd appreciate some advice on my following options... Option 1 - Cover tiles with epoxy damp proof membrane and screed over top to self level. Cheapest way to safely install wood floor but question marks over long term suitability, some tiles may be slightly loose with hollow sections etc. Option 2 - Dig up all tiles and 250mm of soil/rubble underneath and have the whole lot concreted with a proper DPM. Option 3 - Hybrid of the two, screed the hallway and just tile it, but dig up living room to concrete for a wood floor. I've attached plenty of pics and I'd be very interested to hear from any wood flooring experts. If I went down the concrete option would this be sufficient on it's own or would it still need a screed on top too? Any help much appreciated! Steve
Well that's a right balls up on their part and yours unfortunately Builders and joiners laying a floor..... Best way is option 2 if you want real wood Dig it all up Mechanical DPM and new concrete then a liquid DPM over the new concrete when it's cured And use a professional wood floor installer
Full rip out, new concrete base with a working mechanical dpm, leave a minimum of 4 weeks before doing a Rh% test then use a suitable surface dpm and over screed with a high compression strength and flexural strength screed before installation of the wood, it’s a big job and you’ll need to be prepared for the cost. Sent from my iPhone using Tapatalk
Could use Topcem pronto or A38 to speed things up. Also there's the option of battens or 2 layers of ply. Personally I'd go with a 20 or 21mm engineered. Much more stable and more suitable to the UK environment and houses. Sent from my LG-H850 using Tapatalk
Thanks for the replies guys. To clarify CS Flooring's comments, I should also use a surface DPM and screed over the finished concrete? Is this standard practice? The floor was also laid straight onto the existing concrete floor in the front reception and this is the only room where it hasn't failed. However, I'm not totally happy with the result as it does sound a little hollow in places, is this something you'd expect? The concrete finish was also pretty rough so I don't know if that's a contributing factor too. I'm considering ripping it out in this room and screeding with surface DPM, if indeed this is what is required in the other rooms once I've dug out the tiles and re-concreted. Appreciate the input folks.
Absolutely, always surface dpm under wood and the sub floor needs to be better than sr1. Sent from my iPhone using Tapatalk
I've spoken to a few more people about this and they say to be careful when concreting (with DPM) a previously breathable floor, as the damp can be transferred into the walls instead? Is this something anyone has any experience of or know any work-rounds? Cheers
It still releases moisture from the ground just at a much more manageable rate, the only way it would transfer to the walls is if the concrete is almost pure water there’s a reason for Rh% levels that are specified on dpms. Sent from my iPhone using Tapatalk
Exactly, only time I’ve seen damp pushed up the walls was when a leaking pipe was under the dpm Sent from my iPhone using Tapatalk
So I've gone ahead and lifted the quarry tiles, but it seems it's concrete underneath rather than rubble/soil that I'd been told to expect? You can see in the photos the imprint of the tiles on the concrete. I imagine it's just a thin screed over hardcore that was laid when the house was built in 1905? I'm wondering whether this would be suitable to apply a DPM and screed to obtain a good finish, or carry on and dig out? I don't want to start digging and find it's solid concrete all the way!
Drill out a core of concrete and see how deep it goes, you need a Rh% test to be done also Sent from my iPhone using Tapatalk
You could probably put down dpm sheet and have the floor re screeded with fibre reinforced screed now(providing you have the height) You’ll have a proper subfloor then. I wouldn’t Take the sub base up unless you fancy a horrible days work Sent from my iPhone using Tapatalk
So the depth is of concrete is roughly 3 inches in each room, I've put a camera down and looks like just rubble and soil underneath with plenty of gaps in between. I'm inclined to keep going and dig it all out properly but don't really know what the screed options are if I was to leave it.. I've had plenty of horrible days work in this place already so I'm prepared for another few if needs be!
