sub-floor lip

[Guitardedleon]

starting to get somewhere with this bathroom Ive had planned.

so far I've:

Replaced door and lining.
removed all the old tiles
removed the old suite
removed the lino & tore up all the floorboards
re-plumbed
new electrics for heated & lighted mirror and IP65 spots I've had installed.
strengthened the joists and installed noggins

Ive also ply lined the floor , 25mm wbp primed on back and sides with SBR.
screwed to joists at 150mm centers.

however,along the one long edge is a lip of between nothing up to 2mm at the worst point.

this is a join going at 90 degrees to joist direction.

I plan on using a Ditra matt under the tiles.

is this lip ok?

thought it would go when screwed down, but can not fix it.

thanks in advance

 

[beanz]

2mm? That's the worst bit? How flat is the rest of the floor?

 

[Guitardedleon]

2mm? That's the worst bit? How flat is the rest of the floor?

2 or 3mm , yes mate.

rest of the floor is flat as was possible to get it.

room is only 8ft x 6ft so took two boards - has a total of 2 joins on the entire floor.
one long join (across the joists) and one parallel on the second board.

only the long joint is a problem, as mentioned has , at worst, a 3mm lip between boards.
hope this makes sense?

 

[Guitardedleon]

Just checked what was what exactly and the height difference between the two board edges is actually 4mm at the worst point and between 0-1mm most the way along
( highlighted inside of the green boxed area below )

Im due to be at the property at 3pm - so will take a couple photos of the actual floor too.

 

[beanz]

Have you considered SLC? As flat as you could get it, doesn't really say much.. Ditra won't make it any flatter, and I'd be worried about getting a proper bond in the area where you've got a 4mm drop. Personally, I'd latex it.

 

[Guitardedleon]

luckily I have two bags of slc sitting here!
as flat as i can get it is - level in all directions and a lip of less than 1mm. ( other than the area mentioned )

with the small gaps around the perimeter of the room, how would you prevent it from flowing down into the void between floor and ceiling?

also- any preperation tips?

 

[beanz]

You could attach some strip wood/battens around the perimeter.. Or Silicon, if you were so inclined.. as for prep, just follow the instructions on the bag, and make sure it's suitable for Ply.

 

[Guitardedleon]

You could attach some strip wood/battens around the perimeter.. Or Silicon, if you were so inclined.. as for prep, just follow the instructions on the bag, and make sure it's suitable for Ply.

just realised what the real issue is - the timber yard have given me two boards of slightly different thickness's, by a mill or two! (we have had nothing but trouble with their timber, since stopped using them! )

anyhow - some pics of floor:

 

[Stef]

Unscrew that sheet of ply & get a fivers worth of two pences & use them as shims!!

 

[Mr Tiler]

that doesn't look like 30mm centres to me! lol

 

[Stef]

that doesn't look like 30mm centres to me! lol

30mm centres?? You would use a box of 500 screws for one sheet!!

 

[Martyn Leeds]

You might be alright with 35mm centres

 

[Guitardedleon]

that doesn't look like 30mm centres to me! lol

sorry?

the ply is screwed at 150mm - ( apart from where pipes are below )

regarding shims - would that work good enough for tiles?
rather than the pennys ill just grab a bag of packers from the shop. i think its like £3 for mixed bag of 1mm-10mm packers

 

[Stef]

Was only having a laugh.
I would lift that sheet & put shims in & bring it up to the height of the other boards.
A lot cheaper than flinging slc at it.

 

[Guitardedleon]

Was only having a laugh.
I would lift that sheet & put shims in & bring it up to the height of the other boards.
A lot cheaper than flinging slc at it.

that's alright lol.

such a straightforward and obvious solution that I didnt even think of it! :lol:

is there an "acceptable" lip in subfloors? say 1mm between adjoining boards?