what filler to use on external wood cladding

[John Nagelson]

My sister has just moved into a house in northern Sweden, made of wood. Now that she has painted it a lighter colour, gaps are looking uglier between the top strips of wood on the outside, and the timbers they are nailed onto. (The strips are about 4-5 cm wide and 1-1.5 cm thick, and there is about a 4-5 cm gap between them).

Given that the house has stood there since the 1930s, and has been regularly repainted, I doubt that there is any structural problem. But the gaps don't look very nice. In many places they are much too deep (e.g. 3-4 mm) to fill up with paint.

I should add that the gaps aren't evident all over the place - just under about maybe 10% of the strips.

What filler should we use? Something with a bit of flexibility, as used between windows and masonry? Or common-or-garden builders' caulk? Or what??

Cheers,

John

[John Nagelson]

I should maybe also add - all of the timbers are vertical.

John

[Andy Hall]

It would be advisable for her to ask locally.

If it's that far north, then temperatures can drop to -40 or even lower in the winter and can get up to the high 20s in the summer. This is a far larger range than in the UK. There are quite different humidity conditions as well. In the winter, humidity up there is commonly 20% or less.

I've visited the region many times and even had occasion to wander around DIY stores (Jaernia, Bauhas, Ohlin etc) and the product offerings are quite different to the UK in terms of items and materials on offer. For example, B&Q doesn't seem to have much of a line in snowmobiles or big drills for making holes in the ice. Look in the local paper in Luleaa or Kiruna and there are loads of places selling this stuff.

It would also be a good idea if she asks locally about the appropriate repair techniques. I know several people in Sweden with homes built in the 30s and before and there are certainly things that they do and things that they don't that we would do here. Generally, even homes of that age are quite well insulated, but care is also taken to ensure correct ventilation.

The point here is to have local advice about the right material and also technique to use. It would be unwise to simply transplant something from the UK.

it's the perfect week to do the work, though. One can work 24hrs a day (almost); although most people seem to prefer to play - and I don't blame them. Winter is another matter entirely but has its own charms.

[Weatherlawyer]

Really?

I should have thought you'd maybe also add a picture.

But it seems that the outer leaf is made of 2" x 1/2" cladding. All you need do is go down it with mastic. Tell her to have a word with her neighbours.

[The Natural Philosopher]

Exterior grade acrylic mastic..an outdoor version of decorators caulk.

IIRC it's sold as 'frame sealant'. Avoid silicone - paint wont take.