I am getting very confused and stressed, and we haven't even started. I know this job will be difficult (and may get a tiler in to lay and grout eventually), but in the meantime I would love some advice on at least preparing the floor properly for the project.
Room is 30 sq m. Floor is concrete, probably at least 100 years old, now nice and dry after sorting outside drainage, but very unlikely to have form of DPM. Mostly level, two areas of about 1 sq m that seem a bit low (2-3 mm lowest), and nicks of 1-2 mm but not bigger than 4 mm across.
Floor was (stupidly due to bad advice!) coated with Aquaprufe, which failed to stick in most places, except for on areas where concrete was replaced recently. Everything loose has now been removed, and Construction Chemicals advised that the firmly adhered stuff could be primed with SBR and tiled over. Some products seem to demand total removal of any bitumen though, so this is confusing.
Next I am guessing we need to seal the floor with SBR (diluted 1/3? 1/4?).
Will use self-levelling compound in areas that need it. Easiest for me to get is Norcros Pro 50, but that looks like the fibre-based kind that can only be used with a DPM. These aren't big or deep areas that need filling, so what is easiest to use that will do the job?
The tiles I'd like to use are 900 x 600 gauged slate -- ie quite flat on the bottom side, apparently. Big and heavy, but less grouting. I am aiming for a traditional, rusticky-cottage effect (this is for the kitchen-breakfast room), so mirror-flat isn't necessary.
MrFluffy is convinced we're capable of laying the tiles ourselves. He's done ordinary ceramic floor tiles, and we did small slates on the fireplace hearth. Stressful but successful! They both look great, and no problems, but much smaller jobs.
If we lay them, it will take a while, but is there any problems other than the size and weight of these? I understand I should prime the surface with SBR again just before laying. Then -- adhesive: I don't want rapid set. What's recommended for big slate tiles on concrete? I reckon I do need a thick bed, at least 6 mm. For 30 sq metres I think that means around 20 bags, and it seems around £20 a bag! Ouch! Trowel: 10mm or 20mm?
Seal well before grouting, I know too.
Anyone done anything similar to this? Help?!
Room is 30 sq m. Floor is concrete, probably at least 100 years old, now nice and dry after sorting outside drainage, but very unlikely to have form of DPM. Mostly level, two areas of about 1 sq m that seem a bit low (2-3 mm lowest), and nicks of 1-2 mm but not bigger than 4 mm across.
Floor was (stupidly due to bad advice!) coated with Aquaprufe, which failed to stick in most places, except for on areas where concrete was replaced recently. Everything loose has now been removed, and Construction Chemicals advised that the firmly adhered stuff could be primed with SBR and tiled over. Some products seem to demand total removal of any bitumen though, so this is confusing.
Next I am guessing we need to seal the floor with SBR (diluted 1/3? 1/4?).
Will use self-levelling compound in areas that need it. Easiest for me to get is Norcros Pro 50, but that looks like the fibre-based kind that can only be used with a DPM. These aren't big or deep areas that need filling, so what is easiest to use that will do the job?
The tiles I'd like to use are 900 x 600 gauged slate -- ie quite flat on the bottom side, apparently. Big and heavy, but less grouting. I am aiming for a traditional, rusticky-cottage effect (this is for the kitchen-breakfast room), so mirror-flat isn't necessary.
MrFluffy is convinced we're capable of laying the tiles ourselves. He's done ordinary ceramic floor tiles, and we did small slates on the fireplace hearth. Stressful but successful! They both look great, and no problems, but much smaller jobs.
If we lay them, it will take a while, but is there any problems other than the size and weight of these? I understand I should prime the surface with SBR again just before laying. Then -- adhesive: I don't want rapid set. What's recommended for big slate tiles on concrete? I reckon I do need a thick bed, at least 6 mm. For 30 sq metres I think that means around 20 bags, and it seems around £20 a bag! Ouch! Trowel: 10mm or 20mm?
Seal well before grouting, I know too.
Anyone done anything similar to this? Help?!