Victorian house needs help

[VictorianHouse]

Hello, First post here. I am looking for some much needed advice.

70-90% humidity has been a way of life in this house for a long time. I am looking to change this year.

The local area is very wet, with a stream 40 meters from the terraced house, every home along this street has suffered with damp and movement This house has moved causing a cross crack in the render effecting every room in the house with damp. I am looking to patch the gable end this year hopefully. I have taken the blown render off at the bottom of the wall just to have a look. Then moved downwards. Last week i exposed the brickwork underneath the tile dpc by removing the soil Came up one brick course above the slate dpc and hacked off all the render below. Gave the bricks a good scrub and hosed down and have left them, this was on Friday.

I have ordered some 3.5 and 5.0 lime. for the re pointing. 3.5 above dpc with 5.0 below? ratios, there does not seem to be a 1 rule for all here. if in doubt follow the bag? its hansons branded

For the foundations to back fill i have on order by this Wednesday 2 ton of 20/30mm gravel and one 10, and have 20mtrs of non woven fabric to wrap it in. Then decorative on top. This was not intended to be a drain system.

How high up can i take the gravel? the path is 1 course up from the slate dpc, would filling it back level have a negative effect like the render?

Everything around is communal so proper drainage runs are out of the question.

What is the best option for below the tile dpc? re point any gaps best i can then leave it bare brickwork and back-fill. or try to waterproof?

This is where i am confused on the best option to take. bricks want to breath, right so leave it. or take the time to waterproof now before back filling. I didn't dare dig any lower.

I am just diy here. Just want to make this house dry again.

Thanks

 

[Stevers]

That looks like it might be Rat Trap Bond above 'DPC' - it's quite unusual, and weaker than conventional bonds:

Bricks are laid on edge or placed in a vertical position instead of the conventional horizontal position in these brick bonds and create a hollow space within the wall.

Due to the internal cavity, this type of wall consumes less material, but to use this bond, skilled labor and extra care are needed.

 

[VictorianHouse]

Yes it is rat trap

The step foundations are laid one way, then change for some reason half way, where it changes the house has cracked. The path has also dropped. not much i can do about that.

Its was back breaking digging this out. So before back filling with gravel i want to make sure i am protecting the house best i can..

 

[Stevers]

There's something of a presumption on this forum that backfilling with what will be wet gravel may not be effective. Your situation looks like a natural for the 'Zebcolm Trench' not least so that you can see what's going on down there. I can't help feeling that rat trap bond (if below ground level) is a bit of a problem.

 

[Gothichome]

Our home is built with a monk bond, some were around the lower section of exterior wall there should be a vent brick (for lack of suitable name) and the space between the wall should be open to the attic. The idea being air enters the cavity rising between the bricks allowing the bricks to breathe moisture out from the cavity.
Our home has three of them scattered about.

 

[VictorianHouse]

Yes there are air vents. 1 at the front and 3 along the side. The back room had its floor removed and replaced with concrete.

Just had a look. First photo shows the bricks changing direction. This is middle of the house and right where the crack is. The side path also drops here too.

I am ignoring the crack.

Foundation below tile dpc its as far as i dare dig. So i am now confused what the best option is.

 

[Stevers]

It is odd the way the bricks in the foundation layer go from flat to on edge like that - something went wrong with the levels when your house was set out I guess. Although even without ever suffering subsidence, parts of my stone house (built 1879) are not as level as they could be.

For me it's a question of whether the cavity (and just 3" of actual brick each side) will help or hinder water entry. If the water source is on the outside, I reckon water will end up on the inside, so I think gravel no hgher than 6" below DPC then the sainted Zebcolm Trench - though I have no practical experience of producing one.

 

[VictorianHouse]

The black jack was for either the concrete floor before insulating. Or for what i exposed outside. Come summer i will lift the wooden floor. I've had all of upstairs up. Fixing any leaks around the house.

The ka tanking again. On the internal walls before insulating. Or what i exposed outside.

Reason, i don't know if i will full waterproof this cracked render, never done it before lol

3.5 lime and tomorrow i should have two bags of 5.0 for some of the gaps below the tile dpc? Is this correct.

Its raining now. Has been on and off all weekend. Water does not pool up it drains away. Unsure how many courses are left. This was as far as i dare go.

 

[VictorianHouse]

This tile backer board has been outside for 2 years. I have thought about cutting this to the underside of the render. this would keep the gravel and any rain off the wall.

 

[VictorianHouse]

There is a hollow cavity on the brick work. I could push some of these joints out.

I Have left this brickwork and wall exposed over the weekend. As everything was soaking wet. Behind the blown render especially.

Can see the crack, my bet is its top to bottom. 1 dont want to rake out to much till i am ready to re point.

 

[aockenden]

The black jack was for either the concrete floor before insulating. Or for what i exposed outside. Come summer i will lift the wooden floor. I've had all of upstairs up. Fixing any leaks around the house.

The ka tanking again. On the internal walls before insulating. Or what i exposed outside.

Reason, i don't know if i will full waterproof this cracked render, never done it before lol

3.5 lime and tomorrow i should have two bags of 5.0 for some of the gaps below the tile dpc? Is this correct.

Its raining now. Has been on and off all weekend. Water does not pool up it drains away. Unsure how many courses are left. This was as far as i dare go.

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Did I understand this correctly: you’re planning to tank or black jack the inside surface of your cold external walls before installing insulation internally? And you’re also considering to tank or black jack the outside surface of your external walls but also going to use NHL lime for repointing?

I’m confused. These plans don’t seem to follow a consistent approach / theory / worldview. What is your reason for wanting to use any lime at all?

 

[VictorianHouse]

Did I understand this correctly: you’re planning to tank or black jack the inside surface of your cold external walls before installing insulation internally? And you’re also considering to tank or black jack the outside surface of your external walls but also going to use NHL lime for repointing?

I’m confused. These plans don’t seem to follow a consistent approach / theory / worldview. What is your reason for wanting to use any lime at all?

The house was built with lime mortar. why would i use anything else to re point/fill the gaps?

One of the two downstairs rooms has a concrete floor, the other original timber. Not going down the route of taking that up now. At the back is a more modem extension. I have just taken the tiles off the extension kitchen floor leaving bare concrete. ah the difference. freezing cold tiles to warm concrete. The black jack is for this. But its also used outside and i am confused if using it outside will create more problems then not touching the brickwork

The tanking is for the internal brickwork. its like paint, so if water does get through the render again, its not coming inside and has to go back out through the render,. then insulated plasterboard on top.

I am in the process of setting up a fan system. a vent, one in each bedroom. Then have this running 247 extracted out the loft. or to a point the humidity within the house comes back down again.

Running a de humidifier, room at 80%, i love damp clothes. This would drop the room to low 60s before stopping even when set to 40. Turn this off and its almost immediately jumps back up to 80% ex,

Reason i am here is i am confused myself lol, ive done the donkey work getting the soil moved, now looking for ways to protect the house.

 

[aockenden]

The house was built with lime mortar. why would i use anything else to re point/fill the gaps?

Was the house built with blackjack bitumen paint and cement tanking slurries? Why would you use those?

What IWI system are you going to be using? Do you have a thorough understanding of the risks / trade offs of the different approaches you could choose from?

 

[VictorianHouse]

I am researching the risks right now? Easy to return items.

Not many questions answered so far. What do you suggest?

I am open to new ideas. The tile backer board, could be the one. With some 70mm soffit vents added for breath ability. 8m span, 4 or 6 vents? spaced along. keeps gravel off the wall and is not bridging the dpc, < this only came from stevers earlier reply. Black vents would blend in with a blackjack line, then run gravel up to path high.

 

[VictorianHouse]

Lets start with a ratio to fill any gaps on the main wall and below the tile dpc. I do not fancy poking at anything lose here till i have something to fill with. Nothing else can be done till then. Could be lazy and just render over without.

The nhl 3.5, The bag says 1 to 3

Unsure of nhl 5.0 only arrived today, and is in the shed. From my reading it was 3.5 above 5.0 below. happy to be corrected.

 

[malcolm]

A lime pointed wall is great for evaporating water away to the outside resulting in a dry wall. If the dry wall is breathable on the inside and outside it will help suck water from the interior of the house.

The render waterproofs the outside so you won't have that effect, but the question is what to do with that nice bit of exposed lime mortar which should in time dry the lower part of the wall.

Trying to waterproof the wall will only mean water that inevitably gets in won't be able to evaporate away again resulting in a soaking wet wall.

The ideal would be leave the wall as is with a trench outside. A gravel fill will not trap water but scoop the top couple of inches of gravel off and the gravel will be wet as will the wall. A ventilated air gap on the outside of the wall is better.

 

[VictorianHouse]

The exposed brickwork joints have hardened up since being exposed. a lot of it is solid, i check daily. It was soaking under the render. The + crack has been there 15 maybe 20 years with some bodge jobs before. So its let a lot of water in over that time, the reason some of the joints are fully blown out. Its a clear line up the building so far, have held off hacking at it anymore . Unsure if pointing up first is going to be the better option or just render over any exposed brickwork.

I have delayed the gravel now as its been raining. Going to play about with that cement board and see what i can do. Nothing touching the foundation is the best option.

There is a lot more to come off this gable end wall during the summer. Not looking forward to the ladder.

What type of mix, go with the bag recommendations? 3.5 up 5 below? this is all new to me. Why can nothing here be straightforward

 

[aockenden]

Personally I wouldn’t be pointing any brickwork in anything harder than an NHL 2. Depending on the softness of the bricks, it’s possibly worth downgrading hardness even further by moving to a non-hydraulic lime with some pozzolan. And that bag recommendation for 3:1 isn’t lime-rich enough for my taste either. These days my repointing mixes are like 2:1 or maybe 2.5:1. Make sure the sand is well-washed. I’ve made the mistake of using cheap salty aggregates in the past and regretted it once the the efflorescence starts. But if you just plan to re-render with cement or tank or bitumen waterproof over the repointed bricks then honestly why bother with the lime at all?

Your best bet to create a warm dry house is to hack all the cement, plastic paint and gypsum off your walls, both inside and out, then let it all dry out, then redo the whole lot with appropriately selected lime mortars / plasters / renders and other breathable, moisture wicking materials.

 

[VictorianHouse]

If the bricks were in good shape i would not bother, but the joints are blown out , i could push a quite a few of them out, I cannot personally cover over that. What is to stop them from moving in time if i do not re-point. Cannot use cement. everywhere says 3.5 or lower. Just over a week ago none of this was exposed. Had some idea what id find, just new i had to get the soil away from the foundations as best i could and expose the crack and blown render.

How do i tell the softness of a brick. is this something that can be seen in a day / week on a tested area. My head if fried thinking about lime lol