Can you underpin a raft foundation?
Rafts – Underpinning. Reinforced concrete rafts can be constructed independantly of piling or can be tied into the piles if required.
What can be used for underpinning?
Underpinning may be accomplished by extending the foundation in depth or breadth so it either rests on a more supportive soil stratum or distributes its load across a greater area. Use of micropiles and jet grouting are common methods in underpinning.
Why is my house built on a raft?
Sometimes, when ground conditions demand, reinforced concrete slabs or ‘rafts’ are laid and the house effectively ‘floats’ on this raft. Subsidence occurs when the house and its foundations are somehow undermined. In some cases, older properties were built onto the subsoil, without any concrete foundation.
Is underpinning permanent?
The use of piers is considered a permanent solution – one that will not be affected by further changes in the ground surrounding the house – which is why we use this method.
Does underpinning devalue property?
Underpinning will devalue a property but by how much will depend upon how severe the subsidence was and also how recently it occurred. As a general estimate underpinned property is worth around 20-25% less. Despite it being worth less, don’t let the fact the property has been underpinned put you off.
Do you need planning permission for underpinning?
Underpinning work requires very careful planning and execution. If you propose to underpin an existing foundation, approval under the building regulations will normally be required.
Which method is used for underpinning Mcq?
Explanation: Pile method is useful in clayey soils and for waterlogged areas and for walls carrying heavy loads. For underpinning very light structures, the piles are driven along the structure and then brackets or cantilever needles are provided to carry the structure.
What does raft mean in English?
noun. a more or less rigid floating platform made of buoyant material or materials: an inflatable rubber raft. a collection of logs, planks, casks, etc., fastened together for floating on water.