Our Chartered Surveyors often see houses where only part of a chimney has been removed, often just the ground floor or ground and first floor, remaining only in the loft.
Homeowners rarely go to the cost of scaffold to remove the chimney above the roof, or may not be able to if it is shared with a neighbour. So if you are only part removing a chimney, what do you need to be wary of?
In the photograph, you can see where a chimney breast has been removed up to the loft, and then supported on a small piece of timber. As the timber weakens, usually by wood rot over years, it's collapse will send what remains of the chimney stack crashing into the bedroom below. Thankfully, this unsuspecting home buyer had a House Purchase Survey by one of our team of structural surveyors.
When considering whether a chimney breast removal was done satisfactorily, our chartered surveyors will not only look at how the remaining chimney is supported but also damp prevention, fire regulations and ventilation.
Particular care needs to be taken when the wall is a Party Wall with a neighbour. In this case, some methods of support, for instance Gallows Brackets (see diagram) or corbelling are not considered suitable and the Party Wall Act will need to be followed. Increasingly. Local Authority Building Regulation Control are requiring an "I" beam that spans the building is used, so the weight of the remaining chimney is transferred directly to the load bearing walls of the building.
You may or may not need planning consent, depending on whether your home is listed or in a conservation area, and how much of the chimney you want to remove.
No matter what your builder says, you will need to have this done in accordance with Building Regulations. When you come to sell, your buyer (often prompted by his building surveyor) should ask to see your certificate of building regulation approval. If you don't have one, you may face losing your sale or opening up your structure to show that it was done properly.
For advice on all aspects of chimney brest removal and support in your property, of our Chartered Surveyors.