Damp (conservatory floor)

[laserboy]

I have recently built a conservatory on the rear of the house. Originally there was a old sunroom which was built on a substantial concrete base.
I have built the new conservatory on this base as the thickness and structure seemed more than adequate.
The conservatory has a dwarf brick wall with cavity between again laid onto the concrete base.
There is a damp course laid three bricks from the base.
After a couple of months I have noticed some damp on the floor in the corner at the front of the conservatory, not a lot but a few spots.
Also some damp has travelled up from the base in the corner of the brickwork. The cement just looks a bit different from other areas so Im guesssing its still damp?
I have noticed you can buy seler for damp floors, intened for the basement or cellar conversion market which is used to seal out damp, I think one product is called G4?
I want to plaster the internal walls so will need to seal the internal walls to stop any damp coming through.
Is there a product I can paint onto the bricks internally to surpress any damp bearing in mind I need to attach brackets for heating at some point.
Any help at all would be very welcome as I am at a loss as how to go on...
Thanks
Phil

 

[JohnD]

is there a dpm in the floor?

 

[laserboy]

Yes there is a damp course but not sure if there is any damage somewhere, maybe a rip or tear beneath the concrete.
Because the concrete base is two bricks above the ground you can see signs that a damp course layer was used.
I think there is damage to the damp course under the concrete?

 

[r896neo]

Are the DPC and DPM linked?

It sounds like you have built off the slab which has a dpm under under but water is simply tracking up the dwarf wall until it hits your new dpc and then migrating into the room?

Did the sun room have dwarf walls or was it timber framed?

 

[laserboy]

The original sun was constructed with full height single pane glass panels.
The frame was screwed down onto the concrete base.

 

[r896neo]

Ok, So whilst the slab may have a dpm under it if you have simply built your walls on top of the slab water will get in to the bottom few courses of your brickwork and travel up the bricks until it hits your dpc.

This of course will stop the water and it will head into the room.

 

[laserboy]

Thanks that makes a lot of sense, question is how can I sort this prob?
Please can anyone help
Thanks

 

[r896neo]

Do you have room to raise the floor height? If so by how much?

 

[JohnD]

I was wondering if rain is falling on the exposed top edge of the slab, outside?

some photos might help
//www.diynot.com/forums/viewtopic.php?t=129539

 

[laserboy]

the dwarf wall covers the concrete base completely. The concrete base is about 2 bricks higher than the patio. Rain will not fall onto the base.
I have in mind painting the floor inside the conservatory with a two part epoxy liquid damp course.
There are a number of product about. My concern is the internal bricks of the dwarf wall, I would like to plaster the bricks but need to seal before.

 

[r896neo]

I was going to suggest something along those lines and hence why i asked about levels. If you can afford to height-wise you could lay a polythene dpm jablite and float a chipboard floor over it.

Whilst liquid dpm's are fine they are liable to damage and need protected.

Your liquid dpm should cover the floor but also extend up the wall to meet or preferably pass slightly the dpc in your dwarf wall.

 

[laserboy]

Thanks for the advice, I think I will paint the floor with a liquid dpm and then cover with a material before laying the floor, engineered wood maybe?
I think your advice about painting up to the damp course in the dwarf wall is a good idea however how will I get on when plastering the wall?
Do I have to attach board then plaster or plaster on to wall?
Thanks again!

 

[r896neo]

It depends on the brand of liquid dpm you buy but most will be suitable to simply plaster/render straight over. Make sure you check before you buy it. Also may be worth shopping around as they can be suprisingly expensive.

 

[laserboy]

Thanks for all your advice, much appreciated
Yes I've noticed quite a price difference!!
Cheers!