1940 mass concrete bungalow digging up the floors and taking down some walls.

BJC

Hello all.

My wife and I have just bought a mass concrete bungalow circa 1940's. It's approx. 1500 squared feet.

It's energy efficiency is as expected (similar to a cattle shed) and we are beginning the long process of bringing it up to the most energy efficient standard as we can manage. It is a labour of love and will be a few years in the making. With yours truly doing much of the work.

However, due to time constraints and the approaching winter we are testing the waters to see if we can afford to pay for phase one to be done by someone else.

That phase is to:

- Dig up all of the floors, insulate and re-pour.

- Take down two mass concrete walls, one containing a mass concrete fireplace. One is not load bearing, the other will need an RSJ to span about 18 feet (No weight on top of it other than the joist crossover ends and purlin). One wall currently has a radiator on it.

- Reconfigure and upgrade the hot water system to a closed system with a more efficient cylinder that is also connected to a wood stove with a back boiler.

- Install an exhaust flue for the above mentioned stove.


The slab is surprisingly thick for its age. I have done some test digs and there is approximately 3 - 4 cm of dense screed on top of at least 10cm or rougher stuff. Likely left over from the walls and whatever else they had lying around! No signs of damp anywhere yet.

I have already taken down the chimney from the top down to the joists as it was not sealed and letting in huge amounts of moisture. I've felted and patched in the roof. So no scaffolding or high work will be required.

We are in an area of moderate radon risk; I have installed the test meters and we will know more in a couple of months. I have read that remedial radon protection on old dwellings is by no means foolproof. But we'll cross that bridge if/when we come to it. We would like to get the work started by the end of October / early November.

We are novices at this. I have some experience on site and my head on my shoulders but it's a learning process for me also.

Any thoughts on ballpark costs?

And so. Where to begin?

L-M

My brother did exactly what you are starting to do. He bought a we think 1940s bungalow which seems to be a common type across Ireland, assuming it was some sort of council house.

Two of the floors were suspended wooden floors and the rest were concrete. We thought/assumed the building was mass concrete but it was actually a cavity wall that had already been pumped.

Removed a chimney to make more space, it was absolute torture as we weren’t knocking a wall so had to basically cut off what we didn’t want and then kangoo the rest smooth. He was putting a double door in the back of the house to we cut that out and we’re able to drive machinery in the back door! Sounds madness but it helped.

All I can say his he had access to in-laws who had all the required machinery and know how, and access to us as family who were able to help with the the general labour.

What I can say is do not be naive, when you start this job and you strip back the floors and get going, you’re going to end up doing more and more than you originally planned, because why not.

Re plumbing, assuming you’re going to have to re wire the place, chase the walls and put new sockets where needed, so on, so forth.

With a mixture of about 6 or 7 of us out there most evenings and weekends, between delays with getting materials and contractors in to do the floors wiring etc it took over 6 months and I can’t stress enough how much of a labour it was for him, but he was very lucky to be backed up by a very good family and friends to help.

I can’t advise on cost, all the expensive labour was free but I’m sure he spent up to 20k on materials including new kitchen etc

BJC

Thanks for the reply. Only the work mentioned is top priority for us at the moment. The plumbing in the house is dead simple with pipes running to exterior drains that flow to the septic tank. And any wiring I can do myself. We don't expect to be in a fully completed space when the above works are done but the space itself will be established with the walls down, floors done and the wood stove will be in for the winter.

BryanF

Why lift the floors?

TheChizler

Following as I'm planning something similar on a slightly smaller scale, an architect and QS have told us to expect €19k for a bog standard heating system upgrade alone which I can't believe.

BJC

BryanF wrote: »

Why lift the floors?

I'm not lifting them. I'm digging them up to put down a proper DPC/Radon barrier and insulation.

BryanF

BJC wrote: »

I'm not lifting them. I'm digging them up to put down a proper DPC/Radon barrier and insulation.

What’s the plan for wall insulation?

BJC

BryanF wrote: »

What’s the plan for wall insulation?

External insulation is the plan. We'll also be replacing the aluminium double pane windows.

L-M

TheChizler wrote: »

Following as I'm planning something similar on a slightly smaller scale, an architect and QS have told us to expect €19k for a bog standard heating system upgrade alone which I can't believe.

Christ, sounds like you’re getting robbed. My brothers entire renovation didn’t cost him that, complete new hitting system on (radiators) and a new stove.

I’d say price around.

macadam

BJC wrote: »

I'm not lifting them. I'm digging them up to put down a proper DPC/Radon barrier and insulation.

How are you managing the Radon barrier re exterior walls?

BJC

BJC wrote: »

I'm not lifting them. I'm digging them up to put down a proper DPC/Radon barrier and insulation.

Why not just lay the DPM/barrier & insulation on the existing floor and lose a few cms in ceiling height, many of those older houses have ceilings over 3m high so you would have plenty of headroom.

BJC

[Deleted User] wrote: »

Why not just lay the DPM/barrier & insulation on the existing floor and lose a few cms in ceiling height, many of those older houses have ceilings over 3m high so you would have plenty of headroom.

I had considered that but the door frames would be a bit low and it's a good opportunity to conceal some of the new plumbing that will be installed.