Hi,
I recently bought a victorian mid terrace house built around 1890. It needs some serious tlc.
First job is to sort out the sub floor on ground floor level. joists have rotted away in various places as the ground level is above the dpc's atop the sleeper walls in places, and many of the timber plates supporting the joists are sitting half under ground level.
My original plan was to dig the ground level down, build new honeycomb sleeper walls, install all new timber plates on dpc's and larger (probably 150mm joists) to accomodate some insulation.
The problem is, looking at approved document C on the planning portal website, it says that I need to lay at least 100 mm of concrete oversite on a bed of hardcore under this suspended timber floor.
The level of the oversite should be above the outside ground level to avoid flooding i assume. This would block existing air bricks, and also mean that I would have to raise the finished floor height by at least 150mm if I'm to use 150mm joists.
Also, the reason for a suspended timber floor is to allow moisture to do its thing down there, and be vented away. Surely poring a concrete oversite will force any moisture up through the walls?
So, my questions are:
a. can I ignore the regs regarding the concrete oversite, and just throw down a load of aggregate or similar to stop plant growth etc?
b. is it ok for my subfloor to be lower than ground level outside, so long as it is well ventilated and there are dpc's on the sleeper walls?
c. am I wise to steer clear of solid concrete floors because of potential heave due to the clay in my area, and the damp issue mentioned before?
I am ready to tackle the suspended floor myself, and don't like the idea of tons of concrete poured into my house, but if regs force me to pour 100mm, why not add insulation and make the whole floor solid?
I have an independent damp surveyor coming in a few days to have a look, but I'm not sure he'll be able to advise on these issues, and I'd like to know what other peoples experiences are.
Apologies for the essay...
Any input would be greatly appreciated.
J
I recently bought a victorian mid terrace house built around 1890. It needs some serious tlc.
First job is to sort out the sub floor on ground floor level. joists have rotted away in various places as the ground level is above the dpc's atop the sleeper walls in places, and many of the timber plates supporting the joists are sitting half under ground level.
My original plan was to dig the ground level down, build new honeycomb sleeper walls, install all new timber plates on dpc's and larger (probably 150mm joists) to accomodate some insulation.
The problem is, looking at approved document C on the planning portal website, it says that I need to lay at least 100 mm of concrete oversite on a bed of hardcore under this suspended timber floor.
The level of the oversite should be above the outside ground level to avoid flooding i assume. This would block existing air bricks, and also mean that I would have to raise the finished floor height by at least 150mm if I'm to use 150mm joists.
Also, the reason for a suspended timber floor is to allow moisture to do its thing down there, and be vented away. Surely poring a concrete oversite will force any moisture up through the walls?
So, my questions are:
a. can I ignore the regs regarding the concrete oversite, and just throw down a load of aggregate or similar to stop plant growth etc?
b. is it ok for my subfloor to be lower than ground level outside, so long as it is well ventilated and there are dpc's on the sleeper walls?
c. am I wise to steer clear of solid concrete floors because of potential heave due to the clay in my area, and the damp issue mentioned before?
I am ready to tackle the suspended floor myself, and don't like the idea of tons of concrete poured into my house, but if regs force me to pour 100mm, why not add insulation and make the whole floor solid?
I have an independent damp surveyor coming in a few days to have a look, but I'm not sure he'll be able to advise on these issues, and I'd like to know what other peoples experiences are.
Apologies for the essay...
Any input would be greatly appreciated.
J