Rising damp?

[jaye900]

Hi all, I have recently completed a full renovation of a Victorian end of terrace house. After moving in a few months ago, I started noticing wet patches on the ground floor which I am not sure if it is rising damp. The house is solid wall, no DPC done previously, and has suspended timber floor. I have got new pipes and re-wired the entire house. The cement render outside can be found in every single terraced house on my street, so I suspect it has been there for a very long time.

The damp is only found on the front side of the house near the front door and near the bay window (see photos below). On the hotter summer days the wet patch is less, whereas on the rainy days the wet patch is darker. It makes me wonder whether this is rising damp though as I don't see any signs (so far) on other sides, either the wall sharing with my neighbour, or the other external wall which is a park outside and and has plants and trees right on the wall and in theory would attract more moisture. My other suspicion is that it could be that the air vent brick outside being blocked after I have redone the patio at the front of the house. The outer ground level used to be lower with a step into the house, which I have levelled it such that there is a slope from outside to inside for my child who is on wheelchair.

I would appreciate any suggestion and advice on how to address the issue. Thank you.

Before:


After (damp in the first 3 pictures near the door and bay window):

 

[ree]

OP,
1. You dont have any air bricks on the front elevation - below suspended floors a/b's are necessary for front to rear through ventilation
2. Do you have a/b's at the rear elevation?
3. The ground level was already too high before you raised it - you have now turned your front room & hallway into unvented semi-basements.
4. Your method of wheel chair entry might cause minor puddles in the hallway - there are better methods for constructing wheel chair access - just google disability access.
5. You seem to have rising damp, & probably penetrating damp?
6. I'm surprised that you say that there's no original DPC?

 

[RandomGrinch]

Render on the outside of a property may stop moisture getting in, but the problem is, it may also stop it getting out.
The damp around the door frame looks excessive for 'rising damp'.
On the external wall, there appears to be some darker coloured bricks and cracks in the render...

I wonder if rain from the bay, is splashing/pooling here, tracking inside and escaping where it can, alongside the door frame?
It may be worth investigating your gutters during a rain storm, and a slightly wider angle picture of the front of the house may give us some further clues.

 

[jaye900]

OP,
1. You dont have any air bricks on the front elevation - below suspended floors a/b's are necessary for front to rear through ventilation
2. Do you have a/b's at the rear elevation?
3. The ground level was already too high before you raised it - you have now turned your front room & hallway into unvented semi-basements.
4. Your method of wheel chair entry might cause minor puddles in the hallway - there are better methods for constructing wheel chair access - just google disability access.
5. You seem to have rising damp, & probably penetrating damp?
6. I'm surprised that you say that there's no original DPC?

Thanks for the feedback.

1. The air brick is blocked after the slope is built - I am planning to create an opening to let the air flow. I hope this will help but I am not sure if it will solve the problem completely.

2. Yes there is air brick at the rear. Half of it is blocked after the renovation, but I can feel the air flow. Not ideal, but happy to take any suggestion on improving this!

3/4. I saw a neighbour of mine has dug a small trench outside and also expose the first layer of brick. I wonder this will promote ventilation and solve the issue? Or is it best to still apply DPC at the same time?



5. Curious why you think there is penetrating damp?

6. I have added a few more photos of the wall after we have stripped out everything. I may be wrong but I don't think there is any DPC done but would welcome your views...

 

[jaye900]

Render on the outside of a property may stop moisture getting in, but the problem is, it may also stop it getting out.
The damp around the door frame looks excessive for 'rising damp'.
On the external wall, there appears to be some darker coloured bricks and cracks in the render...

View attachment 353202
I wonder if rain from the bay, is splashing/pooling here, tracking inside and escaping where it can, alongside the door frame?
It may be worth investigating your gutters during a rain storm, and a slightly wider angle picture of the front of the house may give us some further clues.

Please see below a wider angle picture of the front of house. Also including a close-up photo of the wall to the left of the bay window which also has the darker coloured bricks. Indeed there are some cracks in the render. Is it better to keep/fix the render or remove completely? I understand what you are saying about the render. Presumably there must be a reason but everyone else on my street has the same render. It makes me wonder and I am a bit hesitant to remove the render completely in case it worsens the situation! There is a neighbour who has dug a small trench right outside and exposed the lower brick though

 

[RandomGrinch]

Please see below a wider angle picture of the front of house

Thanks for that.

Presumably there must be a reason but everyone else on my street has the same render.

The render itself, if the cracks were repaired, may not be an issue.
I could be very wrong, but as I suspected, without gutters on the bay, there may be a fair amount of water dripping/pooling onto that cracked area.
The witness marks running down from the bay seem to tell a story...

Do any of your neighbours have guttering around the bay, or are they all like yours?

Personally (and others may have differing opinions), I would start my investigations here, rather than worrying too much about rising damp, for now.
The slates over the bay look a little old, but it's hard to tell from the picture, perhaps a rework of the roof may better help take water away from the wall?

As I said earlier, I would have a look outside during a rain storm and try and understand what, if anything, is going on.

 

[JohnD]

The house is solid wall, no DPC done previously,

That is most unlikely. Almost certainly, the house was built with a slate DPC. Slate does not wear out, and lasts at least 40 million years.

However, a DPC can be bridged by earth, paving or render or plinths.

Most likely that has happened to yours.
(Correction: that has definitely happened to yours)

Try to find it. Once you do, it will be at the same height all round the house, unless you live on a steep hill.

It is sometimes easier to see at or beside a doorway or doorstep.

It is often directly above or below the original airbricks.

If you still have the floors up you should be able to see it inside.

Do not allow anybody who sells silicone injections near your house.

 

[Odds]

^All of that^

and especially this: Do not allow anybody who sells silicone injections near your house.

A couple of air bricks in the wall under the bay window can make a surprising amount of a difference in allowing damp air to filter away condensation. Houses in that era were always built with them.

 

[ree]

Poster #6,
Personally, I find it rather worrying that you advise privileging the bay roof defects over the facts of a total lack of sub-floor ventilation, and that the OP has sunk (so to speak) his FFL below ground level, given: that the joists in the front room had already showed much rot?

 

[ree]

OP,
Your best bet would be to get an independent surveyor to come in to inspect & give you a possible schedule of works.
My parting comment is that the pic of the rear air brick/vent shows the air brick to be useless for venting the sub-area.

 

[ree]

Poster #8,
How would you install "a couple of air bricks" below the bay window? What kind of air bricks?
How will they "filter away condensation"?

 

[RandomGrinch]

Personally, I find it rather worrying that you advise privileging the bay roof defects over the facts of a total lack of sub-floor ventilation, and that the OP has sunk (so to speak) his FFL below ground level

Thanks @ree.
If you would like to read again, I haven't said anything about privileging repairs to the bay window defects - I suggested...

I would start my investigations here,

As I said earlier, I would have a look outside during a rain storm and try and understand what, if anything, is going on.

A pretty straightforward first DIY task really, wouldn't you say?

: that the joists in the front room had already showed much rot?

Who's mentioned any rot in the front room joists?

Personally, I find it rather worrying that you couldn't see the air brick...

1. You dont have any air bricks on the front elevation

 

[foxhole]

You appear to have built an exterior swimming pools with the only drainage being your front door and air brick.

 

[ree]

Well put. The front door threshold has now been lowered below the path level?
And the only two air bricks - one in the front bay, & one in the rear elevation, are way too high for venting the sub-area.

 

[jaye900]

Thanks for that.

The render itself, if the cracks were repaired, may not be an issue.
I could be very wrong, but as I suspected, without gutters on the bay, there may be a fair amount of water dripping/pooling onto that cracked area.
The witness marks running down from the bay seem to tell a story...

View attachment 353212
Do any of your neighbours have guttering around the bay, or are they all like yours?

Personally (and others may have differing opinions), I would start my investigations here, rather than worrying too much about rising damp, for now.
The slates over the bay look a little old, but it's hard to tell from the picture, perhaps a rework of the roof may better help take water away from the wall?

As I said earlier, I would have a look outside during a rain storm and try and understand what, if anything, is going on.

All my neighbours' bay windows are like mine. My slates are indeed a bit old.

This is an interesting point and you may be right. I was able to compare the wet patch yesterday (raining) and today (sunny). I wonder if the longer wet patch is due to water coming through the frame? There is also some wet patch from outside.

Yesterday (raining all day):


Today (sunny):