Constructing internal walls when renovating your property in France

Internal Walls and Ceilings during Renovation

When I talk of internal walls I am referring to non load-bearing walls. None of the methods for wall building discussed below are suitable for supporting a floor above.

Metal framework

The preferred method of internal wall construction in France is with plasterboard fixed to a metal structure, with glass wool in the middle to help with sound insulation. These metal structures are easy to use (put together rather like Meccano) and consist of metal rails fixed securely to the floor and ceiling, with metal uprights (montants) placed between these, usually every 60 centimetres. The uprights are attached to the rails using self-tapping metal screws.

It is also easy to cut appropriate lengths of upright and rails to created door openings etc. - a shorter piece of rail is fitted at 'top of the door' height between the two uprights.

The rails and uprights come in various thicknesses - the thicker they are the more rigid the wall will be. Greater strength can also be obtained by attaching two uprights back to back every 60cm or by using the uprights every 40cm. Note that 40cm or 60cm gaps are used because plasterboard is 120cm wide and needs to be fixed at both edges, as well as in the middle.

The space between the uprights is filled with semi-rigid rockwool, to improve the sound insulation properties of the wall. Rockwool is sold in standard 60cm width so is very easy to fit in place. Another recommended technique for improving both rigidity and sound proofing is to use two sheets of plasterboard on each side of the structure, rather than one.

You need to alternate the plasterboard on the two sides of the structure - that is, plasterboard on one side of the wall should never end at the same upright as the plasterboard on the other side. Again, for rigidity.

The uprights have holes precut so that electricity cables and so on can be passed through the wall.

You will need an angle grinder or a special tool to cut the metal pieces.

This is one of the most common ways to build internal walls in France, and is easier, quicker and cheaper than constructing a wall structure in wood. The plasterboard is then simply screwed on to this metal structure with self tapping screws, and the joins taped and filled with skim plaster as usual.

Remember to use green 'hydrofuge' plasterboard in bathrooms and wet areas, white in other areas.

 

Plaster squares

Another common method to build internal walls is to use ‘squares’ of plaster, about 60 centimetre square and 5 – 10 centimetres thick, with tongue and groove edges. these are glued together with special glue (available from the same supplier as the plaster squares).

This is very quick to fit but is less practical when there are numerous wires and cables to be concealed - the method doesn’t leave a cavity in the wall, so cables need to be individually buried. A common use for these squares is for 'low walls' as found in kitchen bars, or in supporting walls for bathroom sinks and so on.

 

Wooden framework

More or less the same as 'metal framework' above except it costs more and takes longer, and is harder to sound proof! But you can do it with a saw rather than an angle grinder. That's slightly unfair perhaps, but I don't believe you would ever find a professional using a wooden frame nowadays.

 

Existing Brick or Stone Wall

For putting plasterboard against existing brick or stone walls, there is special glue available. You do not need to build a wooden frame against the wall! You just make sure the wall is dust free, put big blobs of glue on the back of the plasterboard and lift it up to the wall. Press it into place, check it's straight and vertical, and that's it. How easy can you get.

Ceilings

There are two ways to lift plasterboard to ceiling level and hold it there while fixing it in place.

One is hard, and involves two people, a series of struts and supports, and a great risk to life and limb. The other is much easy and involves a machine. I hired the machine, and suggest you do the same.

With the machine, the plasterboard is placed on a surface that holds it in place while vertical, and then this is tipped to horizontal. A handle is then turned that raises the plasterboard to the ceiling level and holds it there. Without this machine, as I know from experience, the job would have taken two of us at least several days – with the machine it took me two and a half days on my own to do 80 square metres of ceiling, including all the cutting to size around the edges and so on. Cost of hire for two days was about £20 – money very well spent. There is still some effort involved in getting the plasterboard on to the lifter, but it is possible for one person and easy for two.

Pretty much all towns will have a place where large machines can be hired, and I would certainly check these out before buying machines that will not be used very much. If you can’t find a hire shop, check in the local builders merchants or diy / bricolage store since they will often hire things out, and if not will be able to direct you.

 

Other Ceiling Tips

I recommend you use plasterboard screws rather than galvanised nails for fixing the board in place, since these are less likely to slip over time as people walkabout on the floor above.

One slight complication is light fittings. You need to cut holes in the plasterboard for these to pass through before lifting it up. Then lift the board close to the ceiling, feed through the wires, then finish raising the board to its final position. Clearly some care is needed in getting the hole in the right place in the board.

As with internal walls, the joists to which you are fixing the boards will usually be 60cm apart so that the edges of the plasterboard can be fixed firmly in place.

If the corners of your room are not right angles (are they ever?) you will need to lower the plasterboard back down and cut the end to shape as appropriate. This is much easier than putting the board in place and then filling the gaps later, so avoid the temptation to fix it in place if it is not quite right.