Box Gutter - Potential House Purchase

graeme16

Looking to purchase a house which has an extension. House is 1900 build with solid walls etc. Extension has been built parallel with the house vs. perpendicular which I suspect is due to roof height encroaching on 1st floor windows. This results in a box gutter between the extension and the original rear wall. See attached drawings for the extension showing 'Code 5 lead lined box gutter detail'. During the house visit there were water marks around the Velux window closest to the original rear wall and also water marks down the wall roughly below the box gutter. The estate agent mentioned she had visited the house at some point where she found a puddle under the velux window which she states was found to be a window seal. Talking to a roofer relative he has informed me of the potential issues of Box Gutters, especially with solid walls. We really love the house and have had an offer accepted and are now obviously concerned that this is an issue. I am looking to have someone inspect the box gutter to ensure it has been designed and installed correctly and inform of current status and remedial repairs required. I believe the extension is approximately 12 years old so am hoping any issues are as a result of normal maintenance required and not a design fault.

Has anyone had any similar experiences or has a similar set-up on their house with any advice to give?

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Flugelhorn

we had a 1906 house with a box gutter that was really far too long (after an extension was built in about 1910) - it leaked and we had to have work done on it - it was 3 stories up from the ground (sloping site) and not easy to keep clear etc

never again!

Dustyevsky

We've had long experience with Velux windows and never had a problem. Ours were fitted by well-qualified tradesmen and only occasionally opened, which probably had some bearing on that.

Currently, we live with a very long aluminium box gutter between our cavity wall bungalow and conservatory. It looks adequate for the job and stays clear of debris, but in situations of very extreme rainfall, it leaks. I'm unsure whether it is overwhelmed, or if water rises above the levels where the cowboy conservatory company screwed it to the fascia, instead of installing it by the correct methods. They were caught out, forced to repeat the work, and we deducted £5k from their final bill, but once a structure like that is pierced, it must lose some integrity.

The only design fault with the gutter itself, is a lack of insulation, which causes condensation to form on its underside when there is a sudden outdoor temperature drop. This results in a few drips through the plastic surround; not a large problem in a stone floor conservatory. This is the kind of thing conservatory companies get away with because they are not usually subject to the attentions of building inspectors, or the regulations they enforce. One would expect on a modern extension such issues would be addressed at the planning stage.

deb64

I have a lead lined box gutter between two gable ends. It's a pain, it keeps blocking up with moss and leaves, overflows and causes damp patches inside the house.

I clear it every 4 weeks as a routine.