Repairs: joinery, doors and kitchens

The bottom sections of stiles/mullions – that is, the vertical timbers supporting the window frame – are classic weak points for water penetration. Rainwater, particularly on a south or western aspect, is driven into the joint, sucked up into the end grain and decays both the cill and the bottom of the stile or mullion.

Solution

Repairs in this situation can be difficult, although it is sometimes possible for a good tradesman to cut out the bottom section of the mullion and let in a new section of sound timber. These are, of course, always prone to further rot if moisture either becomes trapped behind the repair or enters along the line of the scarfed joint.

Note: If done properly the scarfed section should have a joint sloping so that the lower edge of the repair is on the outside face of the timber. But frequently it is done the other way round, which is prone to trapping moisture, or the repair falls out because it is not properly dovetailed and locked into place (see diagram below).

Bedding the new sound timber within a 2-pack resin base can offer an extremely sound repair and extend the life of the components considerably.

Scarfed timber repairs:
(a) This way is not uncommon!
(b) Scarfed in this way the timber post is retained in position