'pon my soul, you're in the wrong hole.....cavity insulation)

[oakysmokyjoky]

Hi. Advice appreciated please. I am chopping out blown bricks and rebuilding the outside face of our house step wall. I find loads of cavity insulation in the wrong hole ...so between the basement garage wall and the wall/sunken pit holding up the steps to the house (the blocks on the right of the photo). There's a 50mm cavity between those blocks and the garage/house blocks (behind the grey bricks) but I'm pretty sure it shouldn't be filled as the cavity prevents damp doesn't it? Question. Should I remove/get the insulation removed or just rebuild the wall and stuff bit more insulation in? Above the garage the house seems to have a good 100mm if additional width too. I can't figure this out. Thanks.

 

[Wayners]

Has the house had an extension? Looks like a cavity from an outside side wall that's now an internal wall?

 

[oakysmokyjoky]

Has the house had an extension? Looks like a cavity from an outside side wall that's now an internal wall?

Hi. No extension. I assume the builder built the garage and house above it as a block...then built the sunken pit with staircase around which helps hold the rest of the house up (we are built into a hillside). back in the late 70s/early 80s - different rules then I guess.

 

[Wayners]

Holes above stairs are for drainage with all the soil behind.
To the left below wall pir light is a cavity that continues all the way down.
That's my guess

 

[oakysmokyjoky]

yes - below PIR is a cavity that's been part filled by the insulation beads. I think this is making damp worse in the garage (coming from the soil pit). It doesn't help that the cavity appears to have been bridged with the render above the blocks. Its a right f'ing mess.

 

[oakysmokyjoky]

So, the cavity is in the right place....but the outside leaf of the garage wall is also forming the structure of the wet pit. All the moisture in the pit is heading down and through the block wall. Is the cavity better to be empty or should it be filled with beads? Seems to be an mix of old mortar, old foam and beads now....with a big gap in the middle. The bags are there just to hold back the beads. Thx.

 

[oakysmokyjoky]

OK. our house structure is **** poor. The undercroft garage for a house built into the hill has 4" walls (brick, 50mm cavity and block on edge) underneath the area I've shown red lines. But the main bit of the house sits on thicker non-cavity solid walls.

Issues: Moisture inside both side walls of garage; 3 RSJs with rusty ends; 4" walls holding up the front bit of the house; RHS cavity filled up with building waste; No ventilation in garage; no damp proofing on the outside of the garage walls at all. I've got a quote for cavity membrane damp proofing to walls and floor but that doesn't fit the structural issues.

What professional(s) do I need to ask to look and find the issues and come up with ways to address them please? We live in South Wiltshire on greensand. I'm even thinking of a partial cut/demolition as its hard to see another way out

TIA

 

[JohnD]

The undercroft garage for a house built into the hill has 4" walls (brick, 50mm cavity and block on edge)

How does that add up to four inches?

 

[oakysmokyjoky]

Sorry, I suppose its 8 inches plus the cavity and a bit of render but its meant to be 15 and a half inches in total as a supporting structural wall.

 

[oakysmokyjoky]

Sorry, I suppose its 8 inches plus the cavity and a bit of render but its meant to be 15 and a half inches in total as a supporting structural wall.

I've just looked at BR2010 online. It looks like its actually OK looking at 2C6/Table 3. For under 12m builds it says 290mm up to one storey then 190mm rest of height to 12m (so that is good for the main bit of the house), and 190mm all the way up for less than 9m...which the front bit of our house is. I think I was a bit freaked seeing the plans and expecting 393mm thick walls around all the basement garage.

 

[oakysmokyjoky]

Can anyone suggest a suitable hand tool that can reach in 12ft+ into a 50mm cavity to drag out a load of building debris please? All the crud there is not helping the cavity do its job. I need something like a thin mattock or a thick pick on a very long handle.

 

[Harry Bloomfield]

Can anyone suggest a suitable hand tool that can reach in 12ft+ into a 50mm cavity to drag out a load of building debris please? All the crud there is not helping the cavity do its job. I need something like a thin mattock or a thick pick on a very long handle.

One of those long fibre, fishing poles, with the sections pinned together, then fix an alloy scoop at the end.

 

[JohnD]

I used a canister vac with a long metal tube. The tube will break up loose material if you poke it. A lot will be sandy and mortar snots. Some large brick fragments I had to pull out sucked onto the end if the tube.

 

[oakysmokyjoky]

I used a canister vac with a long metal tube. The tube will break up loose material if you poke it. A lot will be sandy and mortar snots. Some large brick fragments I had to pull out sucked onto the end if the tube.

I've got a long tree pruner pole (4m,) and I'm going to buy a mini Mattock as that should break up things. Henry will be used for sucking duties!