bathroom floor tiling question.

[handychick]

Hi folks,

First off in reply to gaz, So because I am putting a 25mm WBP ply board straight onto the floor joists, I need to use a special type of adhesive? Im guessing that type of adhesive will be a tad more expensive which leads me to think on my next question.....
Do you think Id be better off putting a 9mm ply floor down first and then putting down 15mm so as to avoid this problem or is this not worth offsetting the cost of the C1S2 adhesive.
In either case thanks for your insight..

Second in reply to Richard, the tiles that would be going on to this area are 10x10 standard ceramic... nothing that unusual or that especially heavy.
Behind the blue plastic is a cavity and then I think its straight onto the "inside" of the roof of the house.
This is why I am a little reluctant to puncture the blue plastic as I presume it was put there as a final line of defence against any water ingress.
Thing is though there are screws already in place which were holding the pb in place which would be difficult to exactly match up on the new tile backer. Maybe Im worrying about nothing on that.
As for getting in behind the wall with the cable coming out, on the other side of that is a cavity and then another PB wall which is the inside wall of an airing cupboard.
There does seem to be some rigid material in behind the blue plastic that isnt just fibreglass insulation but it seems really thin and almost placed there but without opening up the blue plastic I cant really tell exactly what it is.
One option I am thinking of is to open up the blue plastic and put some mini noggins in between the tile backer and the roof boards. Theyd only be about 6 inches long but would provide some rigidity against the board being pushed up and in towards the roof on its right hand side.

thanks,

Paula.

 

[Richard C]

Using 2 layers of ply to achieve the same overall thickness is not what Gaz means; he’s referring to overboading standard floorboards (18mm) with 15mm ply which is not your situation. BAL don’t recommend using C1/C2 adhesive unless the floor is over boarded & they (along with most other adhesive manufacturers) also recommend 15mm as the minimum overboard which is also the BS recommendation; for sure it will probably never fail but in most cases is way OTT. It gives a ridiculously high threshold & 12mm overboard is generally recognised as sufficient in most cases but each floor must be individually assessed. Using 2 layers (9mm + 15mm) of ply will never be as rigid as a single 25mm ply base; my advice is to stick with the 25mm & tile onto that. Single Part Fastflex (C1S2) is relatively new & does provide more flexibility than Rapidset Flexible (C2F2) but I’ve used Rapidset for several years over rigid suspended floors (reinforced in some cases) without any failures or comebacks. Fastflex is, however, cheaper than Rapidset Flexible, so am not sure what you’re comparing it with or where you’re getting your prices from?

By the way, what size pitch & span are your floor joists?

 

[handychick]

Thanks Richard,

By the way, what size pitch & span are your floor joists?

Umm .. im not sure, how do I tell? So far I have barely got part of the old floor up and can only partially see the underlying stuff.

I have this post too which relates to the floor....

//www.diynot.com/forums/viewtopic.php?t=225758&highlight=

thanks,

Paula

 

[Richard C]

With a tape measure, measure the depth & width of the timber joist, then measure how far apart they are (pitch). The joist span is the distance between the walls/beams underneath which are supporting the joists; you should be able to ascertain this from below or you might have to wait until you have got the floor up before you can tell.

 

[tictic]

handychick
buy looking at all your threads/posts/pics you have went to a great deal,in trying to get your bathroom back...
imho..if your thinking off renting i would..

rip out the wbp ply on walls/ceiling
replace wet area with cementbased backerboards to mfr instructions.
none wet areas MR p/board.
floor remove,check spans/dwangs ect.. and if needed sister up joist and add extra dwangs if needed..
then over lay with 22mm or 25mm wbp ply and use a adhesive speced for the job,there are many mfr off adhesive out there..mapei/bal/weber/ardex..etc..
also you could go for MR p/board with a wall tanking membrane..dura/ditra/homelux..etc..and also a floor tanking membrane.
best of.

 

[handychick]

Hi tictic,

The renting thing is a ways down the line and only because I intend to take a year or 3 and travel/work my way round the world but Id want to come back to this house.

The biggest problem I currently have is getting 2 big sheets of 25mm ply delivered. Currently looking at local builders merchants as I live down near kilmarnock but its surprisingly difficult to get them delivered round here. I know wickes will do it but their delivery prices are ridiculous.

Any thoughts from a local view?

thanks,

Paula

 

[Richard C]

I do sympathise; I can just about get 8 x 4’s in the back of my Brava Truckman but I have to balance them on blocks front & back & leave the tailgate open so have to be careful with the weather. Do you have any local independent BM’s? They are usually a much better bet than the big nationals (mostly rip off merchants now unless you spend a fortune with them) & one I used when I lived in Essex would deliver locally free, usually the same day if you ordered before 10:00; how much do Wickes want then?

You could try & “tap up” anyone you see doing local building work, I would think most would drop it off for you for a tenner after their next trip to the merchants.

 

[tictic]

are you in irvine buy any chance?

there is a jewson down at the harbour or there are some small indepedants down that way as well...haggle with them for a good price or free delivery..dont ask..ya dont get..works most times

is there any vans ..transit/transporters in your street?
ask the owner if they would pick it up for you..(happens to me all the time)..

there used do be a small timber yard in dreghorn..but i dont know if he is still there??.

 

[handychick]

im on the total opposite side of kilmarnock up by galston.

Will have a word with some of the smaller BM in kilmarnock.

thanks,

Paula

 

[handychick]

Its a terrible slog but im getting there slowly but surely.

Good job Im not in a hurry

Untitled

• handychick
• 16 May 2010
• 1

Untitled

• handychick
• 16 May 2010
• 1

 

[Richard C]

Your doing absolutely fine; you just need to get the rebuild right

 

[handychick]

Thanks Richard,

And while I remember the joists are 250 deep and 40 across..

Paula

 

[Richard C]

What pitch & span do you have?

 

[handychick]

Hi folks,

Ive decided against buying aquapanel..... mostly because its such a nightmare to get it bought and delivered without paying through the nose for delivery after youve waited 4 weeks for them to buy it in.... grrr .... so Im just going to use 15mm wbp in the shower area and tank the whole area including the plinth.

Im getting the following delivered:

2 sheets of 8x4 25mm for the new replacement floor and 1 sheet of 8x4 15mm to fill some gaps made by destroying plasterboard.

Im planning to buy some bigger sized plain white tiles for inside the shower area with the odd white tile from the same batch placed randomly amongst the 10x10 tiled walls of the rest of the room.
A mosaic border will run through the shower area and also round the rest of the room.

I just wanted to clarify some stuff though


While I am buying the tiles for the shower area, I will be buying the adhesive and also the tanking sealant. I understand that BAL are recommended and I will go with that if that is what is recommended.

What do people feel is the best brand/type/product code for sealant, adhesive and grout?

Also, I may be misunderstanding something Richard said previously.... he said to tank the underside and the sides of my 25mm ply for the floor ... but not the top surface to be tiled....

Am I understanding this right?
Why is this?

thanks,

Paula

 

[GazBAL]

Paula,

Floor
Tanking the back and the edges of the plywood for your floor is not required, however sealing them is ( neat BAL Bond SBR). The reason for this is to stop moisture from penetrating the ply from below and twisting the boards which would cause the tiles on the surface to de-bond. Priming the surface of the ply is not required as we would like some moisture from the adhesive to soak into the board to help get a strong mechanical bond.(BAL Single Part Fastflex)

Walls
Tiling onto a plywood faced wall does require tanking as it a water sensitive background as is plaster and plasterboard (BAL WP1 Tanking kit), and the boards should be adequately braced at 300mm centres. Caution if using tiles larger than 300mmx300mm that the weight does not exceed 30kg per sq m as that is the limit for a tanking solution regardless of the background it is on. Also if large format tiles to use a flexible cement based adhesive and not a ready mixed tubbed one , my recommendation would be (BAL Mosaic-Fix) , grout and silicone containing Microban (anti-bacterial) would be my choice (BAL Microflex & Microseal)

I hope this all helps.

Gary

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