Rising damp?

jeaniemsm

canaldumidi said:

jeaniemsm said:

Grenage said:

You could remove some of the decking, but there's always the option of simply removing it all.  We had decking much like yours; we took it out to lay a patio, but there was already a patio under it.

Ultimately most damp is caused by damp coming through the wall.  Pointing and ground level are usually strong culprits.

Thanks. 
The front portion of the the garden is decked and other half of the garden is grassy area.

At some point when I win the lottery I was hoping to fix up the garden.
One reason why I like having the decking there is when stepping out the kitchen onto the garden it means its on the same level rather than having to step down onto the garden/ step up from the garden to the kitchen.

That is unfortunately precisely the problem (or one of them).

If the ground level outside (whether garden, decking paving, whatever) is at the same level as the floor inside, it is almost certainly above the damp proof course. Which means that moisture in the ground (decking etc) will transfer across to the bricks and penetrate. Note, this is 'penetrating damp' not 'rising damp').

You need to either lower the ground level/remove the decking, or at least provide a gap (filled with shingle?) between the wall and the outside ground so that moisture is not in contact with the wall.

Thank you, when you say provide a gap, do you mean a gap between the decking and external wall - so the decking does not touch the wall?
If so will a small gap say 1 cm be sufficient?

babyblade41

Mr.Generous said:

You can and do get rising damp on internal walls where no penetrating damp or leak is a possibility. Damp injection treatment into the mortar is not expensive and easy for a competant DIY'er. Look at companies like Permaguard (no affiliation but I've used them as a supplier on renovations. The products available now are drawn to the damp and do not require high pressure injection. Unfortunately the plaster can be drawing too, sometimes the skirting. If thats the case then plaster off to 1mtr high and re plaster with plastering sand/portland cement and a damp proofer. Materials are not too costly, labour more so. But do it once properly and the problem is gone.

Never use injection treatments . Find the source of the water ingress and & solve.

Your pictures show many places where water could be seeping in from 

canaldumidi

jeaniemsm said:

canaldumidi said:

jeaniemsm said:

Grenage said:

You could remove some of the decking, but there's always the option of simply removing it all.  We had decking much like yours; we took it out to lay a patio, but there was already a patio under it.

Ultimately most damp is caused by damp coming through the wall.  Pointing and ground level are usually strong culprits.

Thanks. 
The front portion of the the garden is decked and other half of the garden is grassy area.

At some point when I win the lottery I was hoping to fix up the garden.
One reason why I like having the decking there is when stepping out the kitchen onto the garden it means its on the same level rather than having to step down onto the garden/ step up from the garden to the kitchen.

That is unfortunately precisely the problem (or one of them).

If the ground level outside (whether garden, decking paving, whatever) is at the same level as the floor inside, it is almost certainly above the damp proof course. Which means that moisture in the ground (decking etc) will transfer across to the bricks and penetrate. Note, this is 'penetrating damp' not 'rising damp').

You need to either lower the ground level/remove the decking, or at least provide a gap (filled with shingle?) between the wall and the outside ground so that moisture is not in contact with the wall.

Thank you, when you say provide a gap, do you mean a gap between the decking and external wall - so the decking does not touch the wall?
If so will a small gap say 1 cm be sufficient?

Yes, that's exactly what I mean.

1cm would not be enough. I'm not familiar with what Building Regulations or best practice require, but I'd suggest 6-12 inches.

Apart from anything else, over time leaves,soil, general crud will fill the gap and 1cm is nothing.......

stuart45

For an older house with a solid wall like this one it's good practice to have the decking 150mm below the DPC. With modern cavity walls they often put it level with the DPC. A 10mm expansion gap is pretty standard.

FreeBear

canaldumidi said: 1cm would not be enough. I'm not familiar with what Building Regulations or best practice require, but I'd suggest 6-12 inches.

A 6-12 inch (150-300mm) gap is just inviting a broken ankle if you put your foot in it. Either fit toe boards or reduce the gap to 50-75mm (2-3 inches).

shiraz99

FreeBear said:

canaldumidi said: 1cm would not be enough. I'm not familiar with what Building Regulations or best practice require, but I'd suggest 6-12 inches.

A 6-12 inch (150-300mm) gap is just inviting a broken ankle if you put your foot in it. Either fit toe boards or reduce the gap to 50-75mm (2-3 inches).

I'd agree, a 50mm gap would be more than enough.

stuart45

The main problem would be rain bounce for a solid wall. That's why it should be well below DPC. Even a gap would need to be quite big to stop it.
A toe board would stop it, although I never seen one on decking next to the house.