Damp course confusion

[AelinoftheWildfire]

We live in a 1930s (I think) semi. When we moved in we were absolutely clueless first time buyers and over the last 5 years have discovered many, many issues with the house that an experienced eye would have noticed and probably would have avoided purchasing.

One of the main issues we have finally gotten around to addressing is the damp course being covered by the pavement at the side of our house. We've had a damp company out and they advised to get the issue rectified by the council will likely take around 6 years or so. Apparently the brick wetness is at 34% and the plaster is very wet at the bottom of the wall in the hallway. He said it is rising damp as the wall higher up is fine. His recommendation is tanking for that area as an injectable damp course is useless because of the high pavement, does this sound right?

We also apparently have rising damp at the back of the house (I've seen mould on the walls at the bottom so believe this), which he said an injectable will deal with.

Does this sound like the correct course of action for anyone who has had a similar issue? I'm reading such conflicting things about injectable damp courses but I think the high pavement makes it more tricky.

For full disclosure in case it is relevant, our rendering is awful and our gutters probably need doing, not sure if this changes any advice! Thanks in advance!

I'll post pics in comments

Main issue

Back wall of house

*not rendering - pointing of course!

You need @pigletjohn but I can tell for nothing - he will say a big fat no to a damp course.

The air bricks should go into the void under the floor and I think this is below where the existing damp proof course will be ( although I am not certain) so I think that your damp proof course is above where the paved bits are.

Damp proof courses in Victorian houses are usually a line of slate in-between the bricks. Can you see a dark bit in the mortar anywhere round the house, below where the air bricks are?

Do you have a cellar? What sort of plaster is on the walls that are damp (lime or modern pink stuff)? Are the gutters ok above where the wet bits are?

Oh and don't get injection damp proof and tanking. It probably won't fix the problem and might make it worse.

Ignore the Victorian house references. I wasn't paying attention. Not sure what the damp proof in 1930s houses is but might be worth looking for slate anyway.

Can you lower the height of the pavement? If the damp is due to the ground level being too high it's penetrating damp, not rising damp. Lower the ground level outside and you get rid of the problem (hopefully).

Contact the council about the pavement. It is too high. Maybe also your insurers? They may be able to advise.
Repair your pointing!
Looks like you have a solid wall with mortar and soft bricks. Damp will come through that regardless.
A better solution to tanking (holding back the tide) would be hack off internal plaster, install membrane, batten then insulated plasterboard. That solves damp and cold wall. You can do that ‘now’ and it will work.
At the back, repoint, and if possible reduce height of the concrete or just dig out a channel and fill with stones. You most likely won’t need a French drain.
It’s all on YouTube. Don’t rush into anything.

Thanks all. Re lowering the pavement, I did contact the council a while ago and they said as it had been in place for more than 10 years they would require a full survey to confirm that it was causing damage to our property - I don't mind getting this but I've heard getting the council to actually take any action will take years and I'm worried about waiting that long and the damage it may cause. If we can't lower the pavement would repointing and then hacking back and installing the membrane do the job? Just wondering how this bit is different to tanking as that sounded like what the damp guy said

So with the back wall, digging a channel (filling with stones?) and repointing would be better than an injected DPC, is that about right?

We don't have a cellar. Our guttering definitely needs looking at I think though

Sort the guttering first. It might just be that the guttering is overflowing and splashing off of the pavement and onto your wall and that is causing the damp. Damp is best sorted slowly by eliminating different issues one by one until you hit the right thing.

After gutters I would repoint the walls.

If neither of those work then look at digging channels etc.

Whatever you do, don't panic and feel like you have to do something RIGHT NOW. The house has stood for almost a hundred years, it's not going to fall apart overnight.

You say the plaster in the hallway is very wet - this to me implies that there is a direct entry route for water (e.g. damaged pointing, water splashing directly and repeatedly onto the external wall because of damaged guttering). I would first observe for a while - go out when it rains and watch for leaky gutters, puddling on the pavement, etc. How/why does that external wall get wet?

How bad is the mould at the back? Could it be caused by insufficient internal ventilation? Do you open windows when cooking and hanging laundry, do you have an externally vented extractor?

I also live in a 1930s house, and the level of paving at the back is higher than our dpm. This was flagged by our surveyor when we purchased, but in actuality has not caused any issues.

I would try low stakes solutions first - good ventilation, repair pointing and brickwork, remove internal latex paints or external cement renders - see if the situation improves before you move onto more involved engineering solutions.

I read a lot of the posts on www.heritage-house.org/ when we first moved into our home - you might find them interesting.

www.wcp-architects.com/the-rising-damp-myth/

our house has similar raft of issues, particularly internal damp walls. We had our walls pulled down and re- rendered. Turned into a complete waste of time as external issue was not resolved.
get several quotes and professionals- some trades create repeat work when their handiwork fails. - they will blame some other issue impacting their work. Be aware!

water travels and will find the path of least resistance- eg will find the weakest point of entry into a surface on wooden joinery, brickwork, paint, grout, glass etc.

if brickwork is painted- paint will hold moisture in.

check out Instagram - useful for identifying internal wall issues. Helped us understand it’s not how we live - but the materials used.

sympathetic_restoration

Thanks so much all. I've got someone else coming out tomorrow who did work on my friends house recently (guttering and repointing) as her dad was worried about damp so I'm hopeful he will suggest something along the lines of what everyone here has suggested.

I'll have a look at the guttering when it next rains as I'm fairly certain they are an issue.

Thank again everyone, I'll let you know what he says tomorrow but you've stopped me making a knee jerk reaction of getting the injectable DPC!

So he thinks digging a channel and filling with stones and doing the repointing would be our best bet for now. Only issue is I'm not sure if we will get approval to dig up the pavement at the side of the house so off to investigate that

If the gutters are not working then this might stop the dripping from splashing up onto the brickwork and making the walls damp. Definitely cheaper to fix the gutters first as the channel might be totally unnecessary.

Also, what is this contraption and is the poor pointing related to it or the rising pavement, or leaking gutter?

@C4tastrophe i think that the mains gas into the house. Ours looks similar.

This is the gas into the house. The general consensus seems to be the pointing is causing a large part of the issue so that's on the list to fix.
Apparently the guttering looks fine, the guy who came out yesterday said the concrete and the level it comes to, coupled with the crappy pointing is just a recipe for major damp.
The council have said they'll come out and have a look at the pavement, I told them I have two small children in the house so I'm very concerned about the damp so hopefully they'll agree to dig it up and we can put a channel/ drain in.