tiles on farmhouse floor have damp grout

[Unregistered]

I'm after some advice please. I have read quite a few of your posts and there is plently of help out there. So here goes with my problem.
The existing tiled floor was laid in an old property with no damp course so when it is wet only occasionaly and only in some places the grout goes a slightly darker grey as it is soaking up some moisture.
I want to lay new tiles and of course don't want the same problem on the new floor. I've thought of sealing the existing floor but am worried that any damp will stay down and maybe start coming up the walls. I have also considered putting in a floating wooden chipboard/ply floor on top and then tiling. This second option i know is the best but is going to cost quite a lot more.
Anyone got any ideas please? Are there any products that will allo the grout to breathe if i tile over the op? I am open to all suggestions. The room is 40m2 and needs to be completely redecorated.
Thanks

 

[diamondtiling]

Hi there,

why not install an osmosis damp proof course in the walls, its quick and easy with hardly any mess and not very expensive.
If the floor is taking in damp now then that needs rectifying, dig out and start from scratch.

 

[Aston]

I'm after some advice please. I have read quite a few of your posts and there is plently of help out there. So here goes with my problem.
The existing tiled floor was laid in an old property with no damp course so when it is wet only occasionaly and only in some places the grout goes a slightly darker grey as it is soaking up some moisture.
I want to lay new tiles and of course don't want the same problem on the new floor. I've thought of sealing the existing floor but am worried that any damp will stay down and maybe start coming up the walls. I have also considered putting in a floating wooden chipboard/ply floor on top and then tiling. This second option i know is the best but is going to cost quite a lot more.
Anyone got any ideas please? Are there any products that will allo the grout to breathe if i tile over the op? I am open to all suggestions. The room is 40m2 and needs to be completely redecorated.
Thanks

when you say the grout is damp, do you mean around the edges of the floor or all over..??

 

[mikethetile]

its best to take up the floor and lay a dpm, topped off with concrete and a screed
sounds a lot of work but its less work and more effective than messing about with a timber floor which will need digging the floor out and dpm laying anyway

the problem with laying a wood floor over existing is that your old floor may be on hammered earth and will move under the extra weight
if you have old clay or quarries on earth take them up carefully as they have value to a salvage yard

 

[Unregistered]

when you say the grout is damp, do you mean around the edges of the floor or all over..??

There are 2 patches in the middle of the room. Probably no bigger than 1m2 each. There is never any surface water, as in puddles. It is just damp.

It is an "L" shaped room and the 2 patches are in one part of the "L" and in the other there is one patch on the wall of rising damp.

I am looking at the osmosis damp proof kits right now!

 

[Aston]

if its damp all over then as mike says, there wont be a damp proof membrane in the floor so that will need to be rectified...

 

[mikethetile]

this thread is duplicated

 

[DHTiling]

this thread is duplicated

Not any more.

 

[Unregistered]

firstly thanks guys for your input. I've got the idea as a "unregistered" I can't officially thank you, so consider it done.

It seems general consensus is to dig it up and start it again. I sort of new that was the correct solution but sometimes it is great to hear others opinion. However, if I told you there was a step down into the room from the front door and then other rooms off it are a step up again. Would you still dig it up or would you go damp course ontop then concrete? It would save digging it up and also remove the step.

unregistered Ben

 

[mikethetile]

firstly thanks guys for your input. I've got the idea as a "unregistered" I can't officially thank you, so consider it done.

It seems general consensus is to dig it up and start it again. I sort of new that was the correct solution but sometimes it is great to hear others opinion. However, if I told you there was a step down into the room from the front door and then other rooms off it are a step up again. Would you still dig it up or would you go damp course ontop then concrete? It would save digging it up and also remove the step.

unregistered Ben

well that would save a lot of digging just take care that the damproofing is sufficant to prevent damp rising up the walls

I take it the other floors are suspended wood floors

 

[lucius]

Their is aways massive debate on this kind of construction, the original floor would have been some kind of terracota tile or natural stone laid on a bed of lime morter on compacted aggregate which would have allowed the walls to breath so alleviating any damp.Introducing a concrete floor with D.P.M can lock in any damp so forcing it up the walls.Ime not a fan of D.P.C. injection on old walls as it just dosent work it seems the damp companies rely on the waterproof render to keep the damp out though there are lime based renovation plasters available now.The only sure way is to put it back as it was, your decision.
Lucius.

 

[peckers]

Mapei do a liquid membrane called Triblock P It can be used on existing tiles/floor screeds etc, even while they are damp, But no free standing water! You apply the first coat, then after 8hrs apply the second coat at right angles to the first coat sprinkling dried kiln sand into the second coat as you go, then allow to dry over night and then remove the loose sand the next day and then use Laytex plan slc over the top. then it is ready to start tiling, once the slc is dry of course.

Broken Link Removed

I am useing this in the next few days, it is a special order and no one stocks it, it seems. I spoke to the tec guys because i have a floor to screed and they speced this for me..

 

[Richard Edwards]

Peckers

Thanks for your post re Mapei DPM in liquid - Triblock P

This sounds interesting - to me at least as we Install Victorian Floors and sometimes overlay sections of original floors and as the substrate on these Vic Floors is the same as the Farmhouse floor of our guest's house, it might be a solution to some of the issues I encounter from time to time

Once you've done the job - perhaps you might come on and let us know how you got on with it

Thanks

 

[peckers]

Peckers

Thanks for your post re Mapei DPM in liquid - Triblock P

This sounds interesting - to me at least as we Install Victorian Floors and sometimes overlay sections of original floors and as the substrate on these Vic Floors is the same as the Farmhouse floor of our guest's house, it might be a solution to some of the issues I encounter from time to time

Once you've done the job - perhaps you might come on and let us know how you got on with it

Thanks

will do

 

[Unregistered]

This looks as though it might do the trick. The only thing that worries me is the possible outcome of sealing the moisture under the floor . Is it going to appear at the walls? Anyone have any thoughts.....

 

[Richard Edwards]

Hi Peckers

Have you started / completed the liquid DPM /SLC from Mapei yet ? If so what are your comments and recommendations ?

Thanks

Richard

 

[peckers]

Hi Peckers

Have you started / completed the liquid DPM /SLC from Mapei yet ? If so what are your comments and recommendations ?

Thanks

Richard

have just pm you look in the arms under Triblock P/Hardi and a very sick floor!!!

 

[Unregistered]

We have a tiled floor put in a year ago in a barn conversion that gets damp in winter but is dry in summer. The ground level on 2 sides of the barn is higher than the floor. Is it a health hazard to have damp floors? We were thinking we'd just live with it rather than get the builder back again. They are new unglazed composite tiles.

 

[Richard Edwards]

Peckers might be able to help - but one question he will ask ' what do you mean by '' Composite '' regarding the tile structure / type etc.
Are you sure this is moisture coming up from below the tile and not ' condensation due to poor insulation / no insulation and the local air in contact with the tiles falling below the dew-point and condensation forming on the tiles. The test will be to look in the corners and against the cold / outside walls and if the problem is more noticeable there, than say in the middle of the room, then I would consider this first reason before you take any drastic action, such as builder recall and digging it all up or applying Liquid DPM etc

 

[smokey]

Hi the following may be of interest as I have laid 2 floors in an old cottage and in both ways successful.
In the 60s it was common to dig out the earth floor to a depth of 30 cm to 40 cm and fill 20 cm of good broken reject bricks then 10cm of 20mm gravel and finally blind with sand.
After lay a concrete floor followed on top with a screed This was then tiled onto. I have done this in one room and it has been in for 26 years and no problems.
The second floor was carried out as above but on top of the blinded sand I put a plastic membrane which was concreted and screeded over then tiled The edge of the membrane finished at the walls and the walls were lime plastered to allow breathing
Again no problem Hope this helps