Water Sloping Into Victorian Property?

[gohan2091]

Hi,

I have recently purchased a mid terrace house built in 1907 which has been vacant for half a year or more. It has cement render to the back (unfortunately). To the rear of the property, the kitchen floor (half suspended wooden floor, half concrete) has rotten joists all along where the windows are and a blocked air vent (which only just clears the external ground level by a mm or so). I've cleaned out the 2 rear air vents the best I can (difficult as joists are in the way) and I've paid a builder to replace the rotten floor joists with new ones and fit an additional sub floor vent. The rear garden slopes towards the house (see attached photo and arrow directions) and I'm guessing excessive rain water has been entering the house, going into the subfloor and causing the rot. Beside the kitchen is a downstars toilet which has mould growing on the lower external wall.

There are damp patches inside on the wall along the edge of the single window (see attached photo). Since cleaning the vent out this "appears" to have dried it a bit. The vent below this window also only clears the ground level by about a mm. The whole exernal wall at ground level is wet to touch when I felt it today (its not been raining).

To stop the new floor joists from rotting and water sloping into the property i've had different suggestions. Someone said to remove the concrete and shingle the garden allowing water to go into the soil, and painting the external wall under ground level with bitchunin paint. Another person said to have a french drain. Someone else said a french drain is useless in such a small area. A plasterer said injectable damp proofing. Can I have some recommendations please?

 

[oldbutnotdead]

You need to get ground level outside the house as low as possible. So getting rid of the concrete will be a good start.
French drains work but the water has to go somewhere- good odds your gutters drain into the foul drains (but check), if they do then you can link your french drains to the foul drainage (assuming the pipes are low enough). Or if you have a decent sized garden and porous soil (not clay) you could dig yourself a soakaway.
If you can get outside ground level down to subfloor level you shouldn't need injection dpc. Prob need to hack the internal plaster off and redo

 

[gohan2091]

Ok thanks, I'll get the concrete dug up and the floor lowered. How about the recommendation of painting the brickwork under ground level with bitchunin paint? Good idea or bad?

 

[bobasd]

dropping the path level will probably involve removing all the concrete from the yard?
there's also the matter of dropping gullies to the new ground level?
in fact, could you post a pic of the gulley area by the boiler terminal and SVP - something seems weird about the waste pipes arrangements?

painting with bitumen paint is useless - the band of black paint you see below the render is also a bad idea - it wont allow the wall to "breathe".

your air bricks/vents should be 9"x6" plastic air bricks.
did the builder wrap the ends of the new joists in DPC material cappings?

the ladder should be chained and bolted to the wall.

 

[catlad]

Everything not helped by the lack of sunlight.

 

[gohan2091]

dropping the path level will probably involve removing all the concrete from the yard?
there's also the matter of dropping gullies to the new ground level?
in fact, could you post a pic of the gulley area by the boiler terminal and SVP - something seems weird about the waste pipes arrangements?

painting with bitumen paint is useless - the band of black paint you see below the render is also a bad idea - it wont allow the wall to "breathe".

your air bricks/vents should be 9"x6" plastic air bricks.
did the builder wrap the ends of the new joists in DPC material cappings?

the ladder should be chained and bolted to the wall.

Yes probably all the concrete or at least the area beside the house. How deep should it go?

Not sure what the builder used for the wood. It was from a can with the words wood treatment on it which I think he painted on. Nothing was wrapped but I could show a photo if you want to see. According to heritage House website they say floor joists don't need wood treatment, only to be kept dry. Is that true?

How is it best to secure the ladder? A bracket? What's stopping someone from unscrewing it?

I have some photos of my pipework outside. Please can you help me if you see a problem?

 

[bobasd]

dig out to a level below the joist tails that are sitting in the wall.eg the original gulley level (see below).
you dont have to drop the gulley, just dig down to reveal it.
a pic of the new joistings would help.
treatment, as in sprayed chemicals, is not needed - except in certain circumstances.

use a heavy duty steel u-bracket bolted to the wall, and lock and chain the ladder through the bracket.

where's the nearest Manhole?

the air bricks at front and rear of the house must provide through ventilation - are the new air bricks located below the floor levels?

RWP doesn't appear to be clipped.
4 pipes discharge into the gulley - some new arrangement should be used so that a grating an be used to prevent rats leaving an uncovered gulley, and to enable the trap to be cleaned out and drain cleaning to take place if needed.

looking down the gulley opening you will see the salt glaze of the original ground level.
until there's a major refurbishment you may as well leave that jumble of pipes in place around the hopper head.

 

[gohan2091]

dig out to a level below the joist tails that are sitting in the wall.eg the original gulley level (see below).
you dont have to drop the gulley, just dig down to reveal it.
a pic of the new joistings would help.
treatment, as in sprayed chemicals, is not needed - except in certain circumstances.

use a heavy duty steel u-bracket bolted to the wall, and lock and chain the ladder through the bracket.

where's the nearest Manhole?

the air bricks at front and rear of the house must provide through ventilation - are the new air bricks located below the floor levels?

RWP doesn't appear to be clipped.
4 pipes discharge into the gulley - some new arrangement should be used so that a grating an be used to prevent rats leaving an uncovered gulley, and to enable the trap to be cleaned out and drain cleaning to take place if needed.

looking down the gulley opening you will see the salt glaze of the original ground level.
until there's a major refurbishment you may as well leave that jumble of pipes in place around the hopper head.

Can you show me what you mean in the form of a picture regarding the gulley grate? One new air brick as been fitted (the terrcotta plastic one) which is providing very good air flow at the rear. The 2 other air bricks at the rear are not as effective. I'll try again to give them a clean but they are difficult to reach with joists in the way. Same situation at the front. All air bricks are below ground level going into the sub floor.

I'm not sure what's causing the dampness behind the window. Could it be the gap in the missing render? How do I scrub off this black paint? (if that would help).

 

[bobasd]

If you look at pic 583 it shows the square head of the gulley. the head takes the grating. google "gulley grates".
"air bricks are below ground level" what does this mean? can you post pics?
i dont see any "missing render" around the kitchen window but presumably there's no render behind the pipes?
the curved head of the kitchen Pvc frame is well wrong, badly finished, and could be a source of damp.
If you mean the middle room window please pic and point out where the damp signs are?

Dont attempt to "scrub off the black paint" - just leave it.
The bottom edge of the render is ragged - it should have been finished with a Bell cast - all the openings in the render should also have a Bell cast set above them.

The joist tails are sitting on a timber plate - but there's no strip of DPC material under the plate, and in time the plate will rot out.

The "concrete" in the yard only seems to be a thin skim over a gravel surface.
Any lowering of the yard surface will require the manhole cover and frame to be dropped too.

fwiw: i'm surprised that there's no signs of internal rising damp - if the Aertex on the kitchen wall is removed damp might be revealed?
fwiw: closely examine at skirting level around the chimney breast.

 

[gohan2091]

Didn't realise you replied. I'll reply fully when I'm back at the property next week. I live there part time while I get the place sorted. Maybe it's best I post a video showing you the whole area and I'll upload it to YouTube for you to see.

 

[gohan2091]

If you look at pic 583 it shows the square head of the gulley. the head takes the grating. google "gulley grates".
"air bricks are below ground level" what does this mean? can you post pics?
i dont see any "missing render" around the kitchen window but presumably there's no render behind the pipes?
the curved head of the kitchen Pvc frame is well wrong, badly finished, and could be a source of damp.
If you mean the middle room window please pic and point out where the damp signs are?

Dont attempt to "scrub off the black paint" - just leave it.
The bottom edge of the render is ragged - it should have been finished with a Bell cast - all the openings in the render should also have a Bell cast set above them.

The joist tails are sitting on a timber plate - but there's no strip of DPC material under the plate, and in time the plate will rot out.

The "concrete" in the yard only seems to be a thin skim over a gravel surface.
Any lowering of the yard surface will require the manhole cover and frame to be dropped too.

fwiw: i'm surprised that there's no signs of internal rising damp - if the Aertex on the kitchen wall is removed damp might be revealed?
fwiw: closely examine at skirting level around the chimney breast.

I'm not sure what you mean by pic 583. I've uploaded a video of the back and side of my house on YouTube. Please could you take a look?

The air vents are in the subfloor below ground to provide air flow to the subfloor.

I'm getting the back garden concrete dug up next week and replaced with shingle. The builder will fit an anti weed membrane which allows water to soak into the ground.

There is render behind the pipes but not completely. There are gaps where its missing. But it's quite far up the wall not low down. The missing render is below the dining room window not kitchen. I've been quoted £2800 to get the render taken off and replaced with k rend. Do you think that's worth it?

What do you mean by the curved head of the pvc frame? And how do I fix it?

Regarding the timber plate. The builder will come back to fit me French doors and to remove that big kitchen window (and brick up with Thermalite bricks). Can you write me a message to give to him? Basically it's he needs to install damp proof material under the timber plate?

I'm not sure if removing the artex in the kitchen would reveal damp. The walls are in bad shape, I'm getting the whole house replastered soon. Different plasterers are suggesting different things. From multi finish everything to lime plastering the ground floor external walls and krend the outside.