What is a mini pile?
Mini piling is a variation on piling that uses a narrower diameter. This makes them light and inexpensive whilst still being able to support considerably heavy loads. For the most common type of mini piling a hollow steel shaft is screwed or drilled into the ground.
What is a underpinning approach?
Underpinning is a sensitive construction technique for strengthening an existing foundation or placing a new foundation below the old foundation to a deeper depth.
What are the disadvantages of underpinning?
Disadvantages of concrete underpinning: It can be a slow process. It involves excavation, which can be messy. If excavation is required under the existing foundation, you may be unable to use parts of your home. It is labour intensive, which can increase costs for larger jobs.
What to use instead of underpinning?
Structural shoring can sometimes be used as an alternative to underpinning. This approach is most often used when construction must be performed below a structure on the same site.
How deep can mini piles go?
A mini pile generally has a diameter of between 100 and 600mm and can extend to depths of over 50m. Either a reinforcing cage, circular hollow section or a centralised re-bar may be used.
Do you need planning permission for underpinning?
Maintenance on foundations generally does not require planning permission. However, if you live in a listed building or designated area (conservation area, national park, area of outstanding natural beauty) you should check with your local planning authority before carrying out any work.
What are the two main types of underpinning?
Types of underpinning
- Soil strengthening. Where soils are weakened, or extracted, a process of soil strengthening may be used instead of underpinning, which involves injecting a special type of grouting or structural resin foam into the earth.
- Mass concrete method.
- Beam and base method.
What are advantages of underpinning?
Underpinning is an excellent, less expensive and less disruptive way to increase space in the structure. Buying a new property could be expensive if you want more space, therefore underpinning can save you from that cost. Moreover, it will save your from the future expense of extensive repairing.
What is mass concrete underpinning?
The mass concrete (or ‘traditional’) method of underpinning is an established technique, suitable for relatively shallow depths of underpinning. The method is often used for partial underpinning of sections of a building. This is probably the most common form of underpinning undertaken for residential properties.
Why is underpinning necessary?
Underpinning may be necessary for a variety of reasons: The original foundation isn’t strong or stable enough. The usage of the structure has changed. The properties of the soil supporting the foundation may have changed (possibly through subsidence) or were mischaracterized during design.
How do I know if my house needs underpinning?
The most obvious signs to look out for are cracks in the walls. Not all cracking comes from subsidence — for instance, a newly plastered wall may show small cracks, which are quite safe, or minor cracks may appear in older buildings.
What are the types of underpinning and mini piling works?
TYPES OF UNDERPINNING AND MINI PILING Underpinning and Mini Piling works types can be classified in multiple ways. In these guidelines the following classification will be used: Mini piling Mass concrete Piles and beams Piled rafts
What is the difference between piles and mini piles?
The biggest advantage of piling, which makes it suitable for everything from underpinning to building bridges, is that the piles can go right through weaker soil, transferring the load to the more robust soil or bedrock below. Mini piling is a variation on this, using a mini pile with a narrow diameter.
What are the health and safety issues in domestic underpinning and mini piling?
2.1 OUTLINE In the Domestic Underpinning and Mini Piling works activity there have been several health and safety problems including fatalities, injuries, partial building collapses and other damage to structures.
Why use a bill of quantities for underpinning and mini piling?
Underpinning and Mini Piling works projects are generally accurately designed before work commences so measurement contracts are not usually the most appropriate contract type. Sometimes clients or their quantity surveyors look to use a bill of quantities to price variations caused by design changes.