Renovating a Gite in Brittany

Been a bit slow blogging the concrete floor day. After the last week or so of hectic digging and preparation for the 'big' day I've been mostly sleeping and relaxing. Anyway,

The concrete mixer lorry turned up on Thursday as arranged at 8:30 with 6 cubic meters of concrete for the two rooms. The day before several wooden battens at the correct level were placed across the floors. Each 6m batten was supported every meter or so with small piles of mortar to stop them flexing when a straight edge was drawn/shuffled across the top.

There was a slight delay unloading the concrete because I had ordered the conveyor belt attached to the lorry so the concrete didn't need to be wheelbarrowed in. The driver said he didn't have enough room to extend the conveyor and so a few phone calls had to be made to the supplier to arrange a rebate for the conveyor before he would start unloading. After that was sorted we had to use wheelbarrows to unload but as it turned out it wasn't too bad, just a little frenetic as the concrete really rushes down the chute.

Once all the load was in it was relatively easy to shuffle the straight edge left and right across the top of the battens to level the concrete off and pull the excess back to the doorways. By the time we had finished there was only about 5 wheelbarrows too much. Better than being short.

Once we had finished the surface was fairly flat but had a few ripples in it. With hindsight we should have gone back and repeated the process but quite a bit of water rises to the surface as you 'work' the concrete and it was difficult to keep the liquid 'tide' at bay. I'd also been advised that it was possible to come back just as the concrete is setting and use a float to go over the surface and smooth out any ripples and lumps. By the end of Thursday, coming back later with a float seemed like a great proposition.

Having taken a bucket of concrete home to test how cured it was (I didn't fancy driving back at midnight to find it too hard/soft) I went back the following morning float in hand. It turned out that my bucket set slower than the floor and I was a few hours too late. The ripples aren't too back and I reckon I should be able to tile over it, but it wasn't as flat as I hoped. The moral being, don't put off 'til tomorrow what you can do today.

For all the work and deliveries I've had up to now, I have only ever paid a deposit then the balance on delivery or completion. It's standard advice. However, the concrete supplier insisted on full payment up front or no delivery. I should have gone somewhere else, but didn't. So the cockup with the conveyor ended up costing me an 'admin' fee for a rebate on the unused conveyor. I wish they had mentioned that they needed 20m of clear space before I ordered the belt.

Even with the minor hiccups the good news is the floors are in and curing over the weekend. All the pipework is in place for the septic tank guys on Monday and it feels like a real milestone on the project.

Another busy day today getting the floor ready for the concrete delivery Thursday morning.

On top of the hardcore and sand layer we finished yesterday we placed the DPC and large polystyrene sheets. The damp proof course is basically a huge plastic sheet. Each sheet of polystyrene insulation is 2cm thick and two layers are placed on top of each other at right angles to cover any gaps. It was worth the extra effort to ensure the sand layer was flat as the polystyrene sheets are very brittle and any potholes would have caused a problem whilst you are walking around over the sheets.

Unexpectedly a delivery lorry turned up during the morning with 2 3000 litre septic tanks and the various pumps, pipework and stuff for my sewage system. A week earlier than expected. Hopefully they should start on the filter beds in the garden rather than digging large holes in front of the house, otherwise the concrete mixer is going to have a real problem on Thursday. The delivery driver thought they might start installing the tanks Thursday or Friday. We'll have to see.

By the end of the afternoon we had the metal mesh laid on the insulation and I had laid out the electric cables and pipework that will be buried under the concrete. Both the electric cables and plastic water pipes are encased in a plastic conduit (gaine). The water pipes all run from point-to-point without any joints and are fed from a large manifold (nourice). Each conduit is tied to the metal grill with scrap wire to prevent it floating up to the surface of the concrete. It is also fixed to the wall with a push in plastic bracket. The idea of running cabling and pipe under the floor is mostly for convenience. You could run everything from the fuse box, or water main, above ground but getting around doorways gets a bit tricky.

So, tomorrow I've got to fix some wooden battens across the floor at the correct level for the concrete floor. With a straight edge we should be able to shuffle across the battens and get everything flat and level.

brittany renovation

Picked up the floor compactor (plaque vibrante) this morning from the hire shop. They are doing well from me at the moment. It's just a small petrol driven machine with a vibrating plate. I've used one before for laying block paving and it's about 40 euros a day to hire.

Before starting work this morning to cover the soil pipes installed last week we had to order the concrete mixer. We ordered six cubic meters of ready mixed concrete (béton prêt à l’emploi) along with an attached conveyor belt to get the concrete to the far side of the room. The guy at the shop suggested a concrete mix with a slightly smaller gravel mix to get a better finish as I intend to tile straight on top of the concrete floor. The concrete also has a retardant to slow the drying process down to give us time to move it about and get everything level before setting. The whole lot came to 980 euros, a bit more than I expected, but I'm not mixing by hand. So, 6 m³ should be enough for 60 m² at a 10cm depth.

Concrete ordered and the rest of the day was to cover the soil pipes with the extra hardcore ordered last week. To save a delivery charge I also ordered 7 tonnes of grey unwashed sand along with the hardcore in the same lorry. As it turns out it was very lucky I did cos after running the compactor over the hardcore it compressed so much that we ended up shovelling in the extra 7 tonnes of hardcore and then added a layer of about 4 tonnes of sand on top.

We are both bushed having now shifted over 25 tonnes of sand and gravel. Tomorrow it the DPC (damp proof course) and insulation.

BTW – If you got here from google using the search terms hardcore and vibrator, then sorry.

Yesterday in preparation for the gravel delivery this morning I bashed a couple of openings in the walls. A hole for the soil pipes and a hole for the water connection. The man from the water company came for a site survey at the start of this week to discuss adding a new water supply for the house. After a bit of metal detecting he worked out where the water main was and suggested the best place for the water to enter the house. The blue pipe in the photo is the conduit with the plastic water pipe to be connected later. He said it should be 50cm below ground level when it exits the house, so a little more digging outside.

BTW, making holes in these stone walls is a brutal job. In the past I've tried to make a hole just big enough by carefully removing stone or using a hammer and chisel to cut my way through large stones. It isn't worth the hassle. Now I just sledgehammer away from both sides smashing the stone and taking out much much more than you think you need and then repairing the large hole later. In the long run its much quicker and easier.

The lorry with 15 tonnes of gravel/sand mix for the hardcore arrived at 8am and the two of us spent basically the whole day with a wheelbarrow each moving hardcore. By 3pm we had a fairly small pile left and realised that we where short by about 5 tonnes ! I did calculate yesterday that we needed another 3 tonnes but hoped that it might stretch. What I didn't calculate for was that in places I had dug out a little too deep, and surprisingly the hardcore mix actually compressed quite a bit, about 2cm over a 20cm depth. I was going to hire a vibrating compactor next week, but having jumped about on the stuff, I reckon it's going to compress quite a bit.

So tomorrow, at 8am, is another lorry load coming with 7 tonnes (a couple extra just in case).

brittany renovation

Rubble rather than movies.

We visited the local quarry at Corseul today to order the hardcore (herrison) to replace the spoil dug out last week. My original plan was to use large gravel then a layer of sand on top to protect the waterproof membrane. The guy at the quarry suggested for under a dalle beton, concrete floor, using something called 0/30 primaire. I've seen it used under roads and it's a grey stone of various sizes with sand mixed in. Once a vibrating plate machine is run over it to compact everything down there is no need for the sand layer. The good news is that it is fairly inexpensive at about 8 euros per tonne (plus delivery!).

Calculating it out meant I needed 12 cubic meters, approx 18 tonnes, (quarry man said multiply by 1.5), BUT, a lorry load is only 15 tonnes ! So, just the one lorry, and maybe I'll chuck back in some of the rubble ripped out, or more concrete. My head hurts.