Porous Render ?

[FRAN1870]

Hi all,

Most of my vicorian house has been pebble dashed and painted white ... however there are two gable walls that have got that sharp render stuff you put on with a roller ( think its called tyrolean ?? ) .... anyway the rest of the house is fine but one of these walls has penetrating damp.

There are no obvious cracks or lose areas so it must be porous.... I don't really want to paint until we paint the whole property ( big project ) as it will make the rest of the house look dirty.

Is there any clear product I can paint on to seal it up ?

 

[Saycheese5]

A victorian house probably has no Damp Proof Membrane at the base of the brickwork. However the mortar used was most likely lime mortar which made it more breathable. You should have a gap of brickwork between the ground and the base of the render to prevent damp from the ground to be absorbed directly by the cement render. Never seal a damp patch or it could spread to other areas, but you will need to try and find the cause of it. Drops of water from the roof splashing onto the masonry when it rain, for example? If no obvious cause, one way would be to have that area redone with a more breathable material to allow water vapour to escape more easily. Hope that helps.

 

[FRAN1870]

Thanks for the reply ..... It's not rising damp though it's pentrating. The damp patch is about 6ft from the ground level.

I can't for the life of me find the cause ....

 

[vinn]

Tyrolean is not rolled on its applied with a flicker type applicator sometimes called a Gun.
Perhaps the render and Tyrolean was originally applied to cover defects or, hopefully, to prevent penetrating damp?
The surface preparation, and sand and cement render base must be just right for Tyrolean to work properly.

Some Victorian houses had cavities - does yours?

What kind of paint has been used on the Tyrolean?

Why not post photos of the interior damp signs and the exterior side of the penetrations?

 

[FRAN1870]

Inside outside pictures ....

 

[vinn]

cavities?
paint?

The garden wall is butting the rear elevation and possibly allowing penetrating damp to enter.

Its impossible for me to see whats happening in the room - bad light, furniture and the curtain restrict viewing.

Are there any signs of damp or salts on the chimney breast plaster?

Has anyone ever examined for rot, the joist tails in the rear wall, and round the c/breast trimming?

Your neighbour's raw looking render is obviously failing - exactly what is that mix?
Your render has an indentation, and no drip or bell cast above your frame?

 

[FRAN1870]

cavities?
paint?

The garden wall is butting the rear elevation and possibly allowing penetrating damp to enter.

There's no cavity

Its impossible for me to see whats happening in the room - bad light, furniture and the curtain restrict viewing.
The damp is the dark patches ...there's no sign of damp around the inside of the window reveals.

Are there any signs of damp or salts on the chimney breast plaster?
No the chimney breast is fine

Has anyone ever examined for rot, the joist tails in the rear wall, and round the c/breast trimming?
Yes I've been under the floor, the joists are fine ...

Your neighbour's raw looking render is obviously failing - exactly what is that mix?
Theirs is tragic all over the house .. its in a very bad way tbh but not my problem and I can't see it being related as the houses aren't joined.
There is an 6 inch gap between our property and there's

Your render has an indentation, and no drip or bell cast above your frame?

None of the windows have drips or bells .. this is the only wall with a problem.

 

[FRAN1870]

The garden wall has always been there .... this is a new problem over the last 6 months.

There's no cavity

The damp is the dark patches ...there's no sign of damp around the inside of the window reveals.

No the chimney breast is fine

Yes I've been under the floor, the joists are fine ...


Theirs is tragic all over the house .. its in a very bad way tbh but not my problem and I can't see it being related as the houses aren't joined.
There is an 6 inch gap between our property and there's

Your render has an indentation, and no drip or bell cast above your frame?

 

[roy c]

Have a look at the photo of next doors window..There seems to be a big crack over the window,this will be letting water in both properties. It also looks like there maybe more cracks above that window...

 

[FRAN1870]

Have a look at the photo of next doors window..There seems to be a big crack over the window,this will be letting water in both properties. It also looks like there maybe more cracks above that window...

Thanks Roy .... The properties aren't linked ... There's a 6inch gap between the houses