Cavity wall on conservaoty needed or not??

[aslan60]

We have a brand new not quite finished conservatory victorian style that is leaking in water at window ledge level, the glass people came out straight away and siliconed the screw holes this has made no difference.

There is no cavity wall and on the top of the dwarf wall is a porous lintel. We now have a wet plasterboard ledge the window ledge has not yet been put on, and the water is about 2" down the plaster on the dwarf wall also.

What is the best method without botching to correct this any one have any ideas or had similar problems.

 

[^woody^]

Cavity walls are not required, and if you have localised water ingress then that would normally be a problem with the frames or fitting

 

[freddiemercurystwin]

^woody^, whilst lacking a cavity wall may not solve this particular issue that's a mighty bold statement you just made there! I wonder why houses are built with cavity walls?

 

[aslan60]

Cavity walls are not required, and if you have localised water ingress then that would normally be a problem with the frames or fitting

Hi Woody we dont think it is a window problem water is still coming in we think it may be a design fault

 

[aslan60]

Is a cavity wall essential or will we as the builder recommends get away with a waterproof membrane between the wall and plasterboard. Dont want to be having this problem reoccur some years down the line when we have no comeback on the builder

 

[freddiemercurystwin]

A membrane between the board and masonry is a bodge its not much extra effort/cost for another skin of masonry. Besides how's he gonna fit the plasterboard to a membrane?

 

[^woody^]

I wonder why houses are built with cavity walls?

Because a house is mainly walls with a few bits of glass and a solid roof above, whilst a conservatory is mainly glass and plastic with a tiny bit of wall at the bottom.

And as you know, heat will be flying out of the roof and windows faster than any small bit of cavity wall near the floor can help with

 

[aslan60]

A membrane between the board and masonry is a bodge its not much extra effort/cost for another skin of masonry. Besides how's he gonna fit the plasterboard to a membrane?

Hi There not sure I think he is just going to put it between the wall and the plasterboard which has a foam like substance stuck to the back of it To put another wall in now would be a major job as the underfloor heating wire and tiles are now down ;-(

 

[^woody^]

Hi Woody we dont think it is a window problem water is still coming in we think it may be a design fault

I cant think how such a basic construction can be messed up

The frame and cill should be weathertight, and the only way for water to get in in any quantity should be the joint between cill and wall.

If this is properly sealed, then that deals with that.

Solid walls can get saturated under constant rain, but when you consider the millions of homes with solid walls and no penetrating damp, it makes this less likely. In any case the wall should not be getting saturated just below the frames

So the most likely cause may be that of installation (quality) or a frame problem.

Are the external cills projecting from the wall by a good distance?

The wall could be lined with a barrier prior to plasterboarding (ie dry lined). This is a common retrospective method of preventing water penetration internally. But whether this is acceptable on a new build, I would say not - as it does not deal with the initial reason for the water ingress - which will only get worse

 

[Nige F]

We have a brand new not quite finished conservatory victorian style that is leaking in water at window ledge level, the glass people came out straight away and siliconed the screw holes this has made no difference.

There is no cavity wall and on the top of the dwarf wall is a porous lintel. We now have a wet plasterboard ledge the window ledge has not yet been put on, and the water is about 2" down the plaster on the dwarf wall also.

What is the best method without botching to correct this any one have any ideas or had similar problems.

Might be simply the cill has no drip groove under it and the water is tracking back under the cill and onto the inner face of the single brick

 

[aslan60]

Anybody know where I can go to get some impartial advice as I am stuck between the window man and the builder, whilst both are being very helpful with suggestions and I know they will come up with a solution I would like to know it is the right one

 

[^woody^]

A suitably experienced building surveyor should be able to cover this.

For the cost of this, you will have to get both parties to pay half - and be bound by any recommendations

Can you post a few images up - just general views internally and externally where the problem is, and one looking up to show the cill and wall junction.

 

[joe-90]

A suitably experienced building surveyor should be able to cover this.

£300 for ten minutes - no thanks.

 

[freddiemercurystwin]

I think ^woody^ is still on a bender from last night!

 

[noseall]

The sill overhang will all but weather a dwarf wall.

I can not see where water will be getting in.