Read This Before You Tile!

[haveagohero]

This is a guide that I give all new apprentices on day 1 in my company. I hope some of you will find it usefull
This is the way we do things but if anyone has a better way then I am all ears!


Types of tile
Ceramic
Porcelain
Natural stone
Mosaic
Victorian Geometric

Substrate Weight Limits
(A substrate is the surface you are applying tiles to concrete floor, floorboards, plaster etc.)
Plaster Skim on Plaster Board........20KG
Skim and Set Plaster...................28KG
Plaster Board.............................32KG
Sand and Cement.......................40KG
Cement Backer Board..................55KG
Hardibacker Board.......................45KG
Lightweight Tile Backer Board........40KG
Glass Reinforced Cement Sheet.....50KG
Gypsum Fibre Board.....................40KG

Remember to factor in the weight of the tile / m2 AND adhesive and grout

Grout.........2KG / m2
Adhesive....4KG / m2

Tile Weights
................................6mm Notch........................................10mm Notch
6mm Ceramic......... ..14.26 kg/m2 .....................................18.46 kg/m2
8mm Ceramic ...........17.62 kg/m2 .....................................21.82 kg/m2
10mm Ceramic ..........20.97 kg/m2 ....................................25.17 kg/m2
12mm Ceramic ..........24.32 kg/m2 ....................................28.52 kg/m2
10mm Porcelain .........23.88 kg/m2 ....................................28.09 kg/m2
12mm Porcelain .........27.82 kg/m2 ....................................32.00 kg/m2
10mm Natural stone ...31.10 kg/m2 ....................................35.30 kg/m2
12 mm Natural stone ..36.48 kg/m2 ....................................40.68 kg/m2
20mm Natural stone ...58.00 kg/m2 ....................................62.20 kg/m2

Different trowel's for different scenario's, as a guide

Mosaics...........................4mm Notch
Kitchen Walls....................6mm Notch
Good Bathroom Walls......... 8mm Notch
Bad Bathroom Walls...........10mm Notch
Good Floors.....................10mm Notch
Reasonable Floors.............12mm Notch
Large Format Tiles............12mm Notch
Rough Floors....................13mm Notch


Dry Wall Area's................Notched Trowel
Wet Wall Area's...............Thin Solid Bed Trowel
Floors / External Area's.....Thick Solid Bed Trowel
Tiles over 300 x 300.........Large Format Trowel
Mosaics up to 100 x 100....3mm Mosaic Trowel

Terminology and Abbreviations

Backerboards - Board made of cement used instead of plasterboard on walls or instead of ply on floors
Tanking - Waterproofing kit used on bathroom walls
Substrate - The surface you are tiling on to
Priming - Painting acrylic substance on to walls or floors before tiling
Open Time - How long you have to apply tiles to adhesive before it is too dry
Cured - Tile adhesive and screeds can appear dry but are not cured untill fully dry and at full strength.
water Ingress - Water getting somewhere it shouldn't
Screed - A sand and cement mixture used to form a hard floor (self levelling is often referred to as screeding but they are totally different things)
Manual Cutter - A carbide wheel, handle and breaking system used for straight cuts in tiles.
Wet Cutter - An electric machine with a spinning diamond blade that is continually fed with water.
Grinder - An angle grinder that in tiling is usually fitted with a continuous rim diamond disc used for cutting and shaping tiles.
Batch Number - A number printed on the side of tile boxes, these numbers should match on each box for the particular tile that is being used on the same job.
Plumb - Perfectly Vertical
Level - Perfectly Horizontal
Wet Wall - A wall in an area such as inside a shower or around a bath that is liable to become frequently wet.
Back Butter - Apply adhesive to the back of the tile with a notched trowel
Back Skim - Apply a thin layer of adhesive to the back of a tile using the flat edge of the tiling trowel, plasterers trowel or a scraper

S&C - Sand and Cement
SLC - Self levelling compound
PTB - Pourable thick bed
SPF - Single part flexible
2PF - 2 Part flexible
UHF - Under floor heating
WBP - Weather and boil proof ply (also reffered to as exterior grade)
SBR - (eg Bal Bond SBR), A priming and bonding agent)

Background Preparation

Gypsum Plasterboards
Make sure the boards are dry and free from dust, they must be securley fixed and must be rigid, make sure the fixings are flush to the surface, plasterboard usually has two different surfaces, the surface that is intended to take the finish should be exposed. Before tiling, prime with a suitable primer, NOT PVA, something like Bal Prime APD. Allow the primer to dry before tiling.

Newly Plastered Walls
Don't make the mistake of rushing to tile on new plaster, it must be allowed to dry fully before tiling. 4 Weeks should suffice, try and leave a window open to allow air to circulate over the plaster. Make sure the surface is free from dust and loose plaster.
If the plaster has been finished to a shiny, smooth glass like surface brush over it with a stiff brush. Before tiling, prime with a suitable primer as per the manufactures instructions before you tile. If any plaster is loose it will need to be removed and any gaps refilled with fresh plaster or a suitable filler.

Tiling over existing tiles (Not recommended)
You need to bare in mind, weight ratings for the surface underneath the existing tiles, the size of the old and new tiles and the weight. If possible remove the old tiles.
If you cannot remove the old tiles, and are sure that the weight of the old and new tiles will be within safe limits then ensure the existing tiles are securely fixed and not at all loose. Score the surface of the existing tiles, and wash down with a suitable sugar soap. wash again to remove and sugar soap residue then tile.

Plywood
Make sure that if overlaying, the existing floorboards are secure and dry, lay the ply sheets with the cross joints staggered leaving a 1/2 to 1mm gap between boards, screw down at 300mm centres, make sure the screws are flush to the surface. Prime (not pva) then tile. Minimum thickness for plywood to be 12mm WBP ply

Concrete / Screed base
Ensure new bases have been allowed to dry completely, 6 weeks for concrete, 3 weeks for sand & cement screeds. brush then hoover any particulates from the floor, prime with a suitable primer as per adhesive manufacturers instructions

Tile Backer board
Fix securely, make sure they are dry and rigid, No need to prime prior to tiling 6mm boards for walls, 6mm for floors, should be set into 6mm bed of rapid set adhesive and screwed every 150mm in a grid pattern

Tiling over screeded floors with UFH
Allow cement screeds to dry out for three weeks, unless quick setting cement used. Once dried out fully, turn on the UHF an allow it to heat 2 d/c per date, until max operating temp is reached, leave the UHF on at max for three days then allow it to cool to normal room temp. Once tiled leave the UHF off for two weeks, then raise the UHF to desired temp at no more than 2 d/c per day.

Bitumen
Scrape up as much of the bitumen as possible the use a slurry coat of SBR and cement to provide a good key for the tiles

Floorboards
It is not advisable to tile straight onto floorboards as most wooden floors have too much flex in them and this causes the tiles to crack or debond from the substrate. If possible lift the original wooden floor, insert noggins at intervals, place adhesive such as pink grip onto the top of the joists and lay 25mm plywood onto this making sure that any joins in the plywood sheets are supported by the joists and the nogins underneath the screw these down making sure the screw heads are flush with the ply surface. next lay 6mm backerboards into a 6mm adhesive bed and screw down every 150mm in a grid pattern. Tape the joints in the backerboards with matching tape and seal these with rapid set adhesive.

Replacing a Damaged / Broken Tile
Obviously there are a few ways to go about this, this is how I go about it.
For safety wear goggles and gloves.
Start off by scraping the grout from the sides of the tile in question, use a grout rake, or a fein or similar, then drill 4 holes in the tile, in a square formation.
Use a hammer to crack the tile, gently, no need to go mad with the hammer, remember your replacing a damaged tile not trying to make the good tiles damaged!
Remove the pieces of broken tile
remove adhesive from the floor and grout prom the edge of surrounding tiles
fix new tile, grout

[royaloakcarpentry]

Priming...........not all adhesives need the substrate to be primed first. In some instances cross priming has to be done.

Ply thickness is a minimum 15mm for overboarding a floor. It is also meant to be sealed back face and all edges.

Not a bad guide for a first day and gives them the basis to go and research the internet for the other mistakes.

[nick200]

Certainly help me for future

[Wes]

Great post haveagohero Bookmarked for future reference..Thanks

[ayjay]

I've read it: I've decided I'll probably leave it to the tilers in future.

[wine~o]

How do you arrive at the figure of 2KG per sq. Metre for grout ?? Seems a bit OTT to me, would it also not vary greatly dependent on tile size and spacing...

For example, 150mm x 150mm tiles with a 3mm spacing will need far more grout per Sq. metre than 600 x 400 tiles with a similar spacing...

[haveagohero]

How do you arrive at the figure of 2KG per sq. Metre for grout ?? Seems a bit OTT to me, would it also not vary greatly dependent on tile size and spacing...

For example, 150mm x 150mm tiles with a 3mm spacing will need far more grout per Sq. metre than 600 x 400 tiles with a similar spacing...

Its too easy to get into finite detail with things like this, 2kg/m2 is easy to remember and I'm not sure how much of a difference there would be between a 10mm tile with a 3mm grout gap and 3mm glass mosaics with a 1mm grout gap. Better off thinking your borderline with your weights and being under than thinking you're well under and being over.

[haveagohero]

Priming...........not all adhesives need the substrate to be primed first. In some instances cross priming has to be done.

Ply thickness is a minimum 15mm for overboarding a floor. It is also meant to be sealed back face and all edges.

Not a bad guide for a first day and gives them the basis to go and research the internet for the other mistakes.

Quite right ROC! I hadn't picked up on that but then we never over lay with ply anymore.

As far as priming, I would rather prime everything in site than not prime something that needs it. I don't think priming something that doesn't need it would do any harm (correct me if I'm wrong though!)

[royaloakcarpentry]

You could in theory do harm by priming a surface that doesn't need it.

Then again how much of the list is just a guideline, drawn up by manufacturers with a vested interest?

Tiling weight limits........hmmmmmmmm. Did a job last year which turned out to be tile on a mixture of tile and plaster on distemper but had been up for donkeys years. Also areas tiled onto strand board and 3mm ply.

You can't have plasterboard in a shower area. Cement backer boards must be used......What about the many shower rooms we refurbish each year that have stood the test of time for the last 15 years and reveal pristine plasterboard during the rip out!

Tiling over bitumen...All the commercial college trained and apprentice served tilers we have used or use, will tile onto it with some prep. They aren't scraping it off though.

It is a good list, I should have pointed that out in my first post and a nice spot.

[bright_spark]

Excellent post haveagohero..!!

[haveagohero]

You could in theory do harm by priming a surface that doesn't need it.

Then again how much of the list is just a guideline, drawn up by manufacturers with a vested interest?

Tiling weight limits........hmmmmmmmm. Did a job last year which turned out to be tile on a mixture of tile and plaster on distemper but had been up for donkeys years. Also areas tiled onto strand board and 3mm ply.

You can't have plasterboard in a shower area. Cement backer boards must be used......What about the many shower rooms we refurbish each year that have stood the test of time for the last 15 years and reveal pristine plasterboard during the rip out!

Tiling over bitumen...All the commercial college trained and apprentice served tilers we have used or use, will tile onto it with some prep. They aren't scraping it off though.

It is a good list, I should have pointed that out in my first post and a nice spot.

I agree with everything you're saying but like I said if I went into fine detail with every point it wouldn't be a quick reference sheet it would be more like war and peace!

See what you're saying about PB in wet areas and yes we do tile onto pb in wet areas if its sub work and that's what we're told to do but on domestic jobs when I'm giving warranties etc. we never tile onto pb, all it takes is for the custard to let the silicone round the bath or shower degrade and fall out then you've got water passing between the tray/bath and practically straight onto PB. In this situation I know the main worry is where else the water is going but I have been asked to look at more than a few jobs where they just need a couple of tiles replaces round a bath and it turns out the water has wicked 4 rows high and its a full rip out job. But as you say we have ripped out plenty of jobs where the job has been tiled onto PB or plaster and the walls have been clean as a whistle when the tiles come off.

See what you are saying about a lot of it being manufacturer recommendation but the problem is that if you don't follow the manufacturer guidelines and something goes wrong with the product you are looking at footing the bill to put it all right and for that reason I follow manufacturer recommendation as much as I reasonably can.

A lot of what we do is perhaps overkill but at least I can offer a 5 year guarantee and sleep at night knowing my jobs are solid. Its horses for courses but I take a lot of pride in knowing that I do everything I can to leave a job that's going to last a long time

[Razor]

I think it's a great post and well worth being made a sticky eh Mods?

[moderator2]

I think it's a great post and well worth being made a sticky eh Mods?

Mod 2 agrees. Maybe wait to see if the other Mods agree.

[Wes]

Hear hear

[moderator6]

I agree too. Now it's a 'sticky'