My friend has a 1950's semi-detached house and it has concrete gutters running parallel with bottom of sloped roof, both front and back of house.

It seems is starting to leak as you can see small orange stain lines under the gutter where the concrete is joined, and also there is a bit of damp at the top of the rooms inside in some places.

The technical name for concrete guttering is Finlock gutters. Finlock gutters are made from pre-cast concrete and lined with bitumen. Finlock gutters are often found on domestic buildings where they serve single dwellings to terraced blocks of houses.These gutters are supported on the external walls of properties and were normally installed many years ago and now have come to the end of their life expectancy, many Finlock gutters when removed are found to be quite crumbly. Certain designs of Finlock Gutters have a loose front section these are creating problems when they become detached and are a danger to people passing below. Age and weather conditions will cause concrete gutters and Finlock gutters to move and shift, resulting in breaks of joints between blocks causing leaks and building damage.

Sometimes you can see the white stain marks on the underside of the gutter. That is where they have been leaking over the years and the water has stained the concrete.

The problem with Finlock gutter are the same with many things that are cheap to build and that is that when they do fail they fail completely and ultimately cost more to maintain than they did to install in the first place.

Once the seals go in the gutter sections, they leak quite badly and because they cross the cavity a good proportion of the water can actually leak into the house as well as into the cavity causing damp which will ruin interior decorations and down the outside of the brickwork which will damage the bricks, causing great discomfort to the occupants.

To fix the Finlock gutter, you can have them either re-lined or cut off. Apart from leaking they are known to suffer from condensation problems.

The replacement to these gutters usually requires the removal of the bottom row of slates or tiles to expose the tiling batten. New system fitted into the gutter and the roof slope leg extends to this exposed batten. Corner sections and stop ends are factory fabricated, as are outlets. The final installation provides a leak free system, which will not discharge into the building.

One choice is to have aluminium gutters installed. They were normally manufactured on site - by a machine in the back of a van which takes a roll of flat aluminium strip and bends it into the appropriate cross section.

They are seamless to the extent that straight sections are made in one piece with no joins - unlike plastic guttering which comes in standard lengths which have to be joined. There still have to be joined in order to go round corners, of course. But these are riveted together using proper corner pieces, and sealant is used - so the whole assembly is rigid and leak proof.

Another choice is P.V.C.U, it provides both a decorative and protective finish to the roof while allowing industry specified levels of ventilation back into the roof area to avoid condensation problems. It should come complete with matching corners joiners end capes, and a selection of roofline accessories to add that finishing touch to your property.

There may many patented, ready-made guttering system there, please talk to a Finlock guttering removal specialist for more information.

Good news is once the guttering has been replaced the property will become maintenance free and it would take an expert eye to be able to point out that concrete Finlock was ever present in the first place.