Old beams maintenance - restoring and

renovating property in France

Beams and Woodwork

Many old houses in France have exposed beams, and very attractive they look too. If they have been kept dry they will last hundreds of years with no particular care and attention. To ensure this continues, renovation projects usually include a review of the condition of the exposed beams, then some sanding and removal of decayed wood, followed by treatment of the wood against wood-boring insects.

Remember that even if wooden beams look to be in a bad state they are usually still very solid inside.

It is often said that woodworm etc can not eat into the hard centre of the wood, so no real harm can be done. This is usually the case but not absolutely always. Sometimes old beams were made from softer wood - poplar, for example, instead of oak - and this is more vulnerable to being eaten right through. Even with old oak I have had cause to cut through a few old beams and on one occasion there was certainly damage to the centre of the wood. Very unusual though.

The usual way to verify the condition of wood is to bang three inch nails into it with a hammer. If the nail won't go in or only with difficulty, the wood is fine. If the nail goes in easily there is a likelihood that the beam needs replacing. More pessimistic people do the same test with a screwdriver or a stanley knife.

The main 'weak point' for beams is where they are set into the wall at the ends. The humidity of the wall can cause dampness in the wood which can lead to problems, so this is the part that should be tested.

roof structure in an old barn

If you find that the beams do need replacing you are likely to need a professional, since the beams probably act as support for the floor above. In any event, since there are load-bearing and other structural considerations I will not discuss it here.

 

Initial Process

Having verified that the beams are in reasonable condition, the next stage is to remove all the decayed and crumbling wood from the surface, until you find solid wood. The tools to use will depend on the amount of wood to be removed. The amount of sanding will be greater if, like some of our beams, the wood has been painted or gloss varnished at some earlier stage - in this case, even sandblasting (with care) may be the best approach.

Having done that you will want to sand the wood to remove residual damaged wood and provide a clean surface.

A quick wash with detergent water should then suffice to finish the preparation.

 

Treatment

There are a multitude of treatments availale for wood against wood-boring insects. The most common in France is Xylophene.

These treatments should ideally be brushed vigourously onto the wood, with a sprayer used for inaccessible corners and gaps if necessary. Two coats is recommended for sound wood or three coats for infected wood.

Ideally you will not be living in the property at this time, since the fumes tend to get everywhere and are quite noxious. Also, wearing suitable protective gear is imperative.

Sometimes more intensive wood treatment is recommended by specialists. This will typically involve drilling holes in the beams every few centimetres and injecting treatment at high pressure into the heart of the wood. This is usually beyond the scope of DIY. I am not convinced personally that the benefits of doing this are significant, since the damage to wood is largely around the surface of the wood and the holes drilled could weaken the wood more than any insect. I am not one to get over-neurotic over wood treatment of wood that has been standing without any treatment at all for 200 years. You are welcome to disagree with me on this.

renovated roof, inhabited barn

The treatment of the wood should be redone every few years to ensure continued protection. In any case, the risk to the wood is much less in an inhabited, restored, clean, dry and broadly insect free building than in an old derelict building.

 

Termites

Note that none of the above applies if you have evidence of termites at the property. Termites always need professional treatment, regardless of what is says on the packaging of the product you are using for treatment. Any confirmed evidence of termites at your property must also be reported to your local mairie.

For information about adding a new beamed ceiling / floor SEE HERE

This information is provided by renovation of old beams