Wall Damp - Dry Rods done by previous owner(s) into the brick?

[RussB32]

I have a 1930s semi with a minor damp problem on the front 2 walls.
The house is situated quite low down, around 1-2 feet lower than the path infront of the drive. I am currently addressing the drainage and I am going to dig away and lay course gravel then a top layer of finish gravel around the brick work of the house. Currently there is around 2 inch of finish gravel and some slabs laid poorly around the brickwork.

The previous owner looks to have installed dry rods but has drilled them into the brick and not the mortor course. Will this even work?

I am very tempted to do this again but properly.
See images below that show the dry rods into brick and the rising damp we get on very wet days.
Any advice would be very welcome

 

[Ivor Windybottom]

The injected damp courses were always done into the brick in the past. It doesn't really make sense but it's how it was done. Obviously it hasn't worked in your case. Many bricks just weren't absorbent enough for it to do anything. I can see how it would work in sandstone, but not bricks.

Injecting into the mortar seems a bit more logical. It's probably worth a go. It looks like it's a pretty straightforward DIY job too.

But also have a fundamental review of all gutters, downpipes and drains. Old soakaways are often past their lifespan and need renewing. The outcome may be that the water is being pressure-injected into the soil around your wall from a cracked pipe underground.

Also check the gradients of all paving, to ensure it's not funnelling water towards your house. If so you need an ACO or similar drain to pick it up and take it away.

 

[JohnD]

The damp patch in the first pic is so localised that there is pretty sure to be a source of water. Most likely centred on the middle of the base of the mountain shape.

It is so high at the corner of the house that the source may be above.

The drain does not look beside the damp patch so it might be a leaking pipe. It might be in the ground on the outside of the house, or it could be under the floor or even against the inside wall, like a washing machine, sink or radiator. Some photos of the inside would be informative.

Look at the roof and gutter above, and any pipes or overflows in the wall in case water has been dripping down.

Stand back and take wider pics of the entire wall, all the way up to the roof, both sides of the corner.

Scrape away the gravel from the foot of the wall and see what is concealed beneath it. Look for the original DPC which is mostly likely slate in a mortar bed two bricks above where ground level used to be when the house was built. Dig around the downpipe gulley and see which way the drain goes.

The recent paving and gravel may already be higher than the DPC, so do not raise the level any more. Most likely it needs to be reduced.

Forget about the useless rods and concentrate on finding and rectifying the source of water.

 

[Ivor Windybottom]

The various damp-proof additives attract mixed opinions. Some say they're useless, others say they're wonderful (usually those selling them). In reality they definitely have some value but are more of a damp-resistant treatment than damp-proof.

I agree with the above that there's something severe going on here though. My bet is on the driveway funnelling water all together into that one spot. But it's impossible to tell from the other end of the internet.

 

[RussB32]

A bit of an update, no major work done yet but I've had a dig around out the front. Beneath the top layer of gravel were some old slabs, which were angled slightly into the house, I have removed all of these. Beneath those is a mix of stone, brick pieces and mud. You can see from the photo there are at least 4 more layers of brick beneath the painted original level. I am not entirely sure where the original DPC would be?

 

[RussB32]

Here are the issues internally.
I am very keen to sort this damp issue as our next project is to sort out our god awful hallway.

The red lines indicate where the damp is on prolonged days of rain. This doesn't happen very often. But we regularly get around 1/4 of the area damp on an average wet day.
The cupboard containing the electrics is completely unfinished inside.
The hallway is difficult to heat due to the large amount of external solid brick wall. On days when its particularly bad I use an electric fan heater pointed at the walls, combined with a dehumidifier to help remove moisture.

I should also add we keep a close eye on our total house humidity and have 3x good size dehumidifiers throughout the house.

Some minor damp showing in our front room, this wall is the front facing wall, where I have dug away the gravel.

 

[RussB32]

I am thinking of digging out a 2 foot wide channel down to the lowest brick around the house, and re filling with new course gravel. I will then re gravel but not go as high up the house as it was orignally, so at least 1, maybe 2 bricks below the painted line.
This should help by exposing more brickwork to airflow? And reducing the ground contact which could help promote rising damp.

Any other suggestions would be greatly welcomed.

 

[Ivor Windybottom]

It possibly never had a DPC originally. Do you know when it was built?

That downpipe/gully next to your door is your number one suspect. You need to find out where it goes and check the pipes. My guess is that the pipe is blocked about a foot down and is cracked, so it's spewing underground and your house is acting as a soakaway. If so then it needs a new soakaway (or connection to the sewer) and all new pipes and gully. The stuff is surprisingly cheap, you sound like you're capable of DIYing the job.

First, dig out a couple of deep holes in the worst spots, to the bottom of the brickwork. Put a board over to prevent any human limbs or wildlife getting in. Have a look after it next rains heavily. If they're filling with water then there's an issue.

Also get a coat and umbrella and have a walk around while it's raining heavily. You may see things going on that all suddenly make sense of it, e.g. a spewing downpipe or a drain backing up.

If it's just general groundwater then it may be best to replace the gravel with an impervious surface that leads into aco drains so the water can be piped away, e.g. into a soakaway well away from the house.

Take your time working out what's going on before you start randomly fixing stuff that may not need it.

 

[stuart45]

I have a 1930s semi with a minor damp problem on the front 2 walls.

It possibly never had a DPC originally. Do you know when it was built?

It should have one if built in the 30's.

 

[foxhole]

Photos of roof, Gutters?

 

[JohnD]

There appear to be gaps between bricks where there should be mortar.

Long term leaks can wash lime mortar away.

Keep digging until you can see the damage. It will be worst near the water. You can wash out the mud and dirt with a hosepipe and repack with a stiff sand and cement mix. You may find the source when you look. Clay gullies and drains beside an old house are usually cracked and leaking.

Looking at your downpipe, it looks like the original gully is well below current ground level. This might be because the ground level has been foolishly raised, or because leaking water has washed away the soil benesth so the gully subsides. Or both. When it was built it will have been at ground level.

The original DPC will be two or three bricks above where ground level used to be when the house was built. It may be visible under the doorstep. It will be at the same height all round the house, so look at the back and sides. Look at similar nearby houses and their ground level relative to the doorstep. A wire brush on the mortar joint may expose it.

You need to show pics of the damp patches, with pics of the outside wall at this point, and any water sources or damage adjacent.

 

[Ivor Windybottom]

There's no point digging all over the place looking for some big hole, there won't be one. Just that one empty perp joint would be enough to fill the basement with water.

I'm guessing it's a wooden suspended floor. In which case there's probably a swimming pool under there. It would be a good idea to look under there somewhere around that door. Use a drill and endoscope if you're bothered about the flooring. Look after heavy rain. The issue may well be a perched water table. This is where there's an impervious basement floor, probably oversite poured concrete. The walls are porous all over the place, the groundwater is getting in somewhere and filling it all up, then sitting under the floor for days after, seeping into the walls and rising up them.

But you're wasting your time trying to find the leak. If you fill one another will develop. Get back to the source, find out why the surrounding soil is getting so wet and eliminate it.

Get rid of the groundwater then look at getting a DPC. You don't want to rely on a bit of water-repellent liquid to try and keep back gallons of groundwater, it's just not capable of that. Longer term, have a dig into the pointing lines, there may be some slate or bitumen in one. But if there is one then it's evidently failed. Put a good quality injected treatment into a pointing line that's two courses above the ground and below the floor. You may need to do the same on internal walls, or you may find this issue just goes away once you get rid of the underfloor swimming pool.

 

[Old Salt]

Where is the ground level on neighbouring houses?
Do they have any problems?
I would be taking down the ground level to find the original as built level and Checking out the drain pipe and where it drains to. Atco drains are a good shout too.

 

[JohnD]

But you're wasting your time trying to find the leak.

If there is a broken drain (likely) or leaking pipe, then finding and repairing it is not a waste of time.

 

[Ivor Windybottom]

I'm referring to a previous suggestion of looking for leaks in the wall. It's pointless, all walls are porous if the ground's saturated with water. Concentrate on finding the water source, not on trying to build a dam to hold it back.