A: You will need local authority approvals in certain circumstances. By Local Authority Approvals we normally mean Planning Permission and/or Building Regulation Approval.The main source of guidance in this area is the Government’s website,The Planning Portal.
Q: How do I work out whether I need local authority approvals?
A: Contact us at Hollybush Buildings.
Q: Can I put my building on paving slabs/tarmac?
A: The simple answer is no as any building is as good as its foundations, and concretebuildings are no exception to this rule. A concrete raft base is required to provide the structural stability for our building. Slabs/tarmac/paving slabs or blocks can move and result in the building moving.
Our base recommendations are for a minimum 100mm concrete cover over the whole area, with a thickening around the edges to a depth to suit local soil conditions, typically 450mm. The addition of a concrete mesh to provide strength and a damp proof membrane (dpm) is also recommended.
Q: How big should my base be?
A: A concrete garage base should be 6″ wider and 6″ longer than the external size of your garage.Make sure that the base is above the surrounding ground level, normally allowing at least 1″ (25mm) out of the ground.
Q: How thick should my concrete base be?
A: This will depend on local soil conditions. A minimum of 4″ (100mm) cover on 4″ (100mm) hardcore, with a strengthened perimeter beam, say 18″ x 18″ (450mm x 450mm), will suffice for average soiled conditions.
If you live in a clay soil area, these dimensions will have to increase, but the design should be tailored to suit. You would be well advised to include steel mesh reinforcement in such areas.
Q: Can I have a base larger than the building you will put on it?
A: Simple answer, Yes! We need a flat, level and square slab, that must be a minimum 6″ (150mm) longer and 6″ (150mm) wider than the external dimensions.If you want to cast a bigger area, no problem, but you will need to mark out where you want the building to go.
Q: What do I need to take into account when designing my base?
A: Apart from the sizes and ground conditions listed above, your base should be perfectly square, Flat and level. Once you have built the formwork for your base, you should check for square by measuring the diagonal dimensions – they should be the same if your base is square. Adjust until they are.
Don’t cast the base with any fall at all. Concrete panels are rectangular, and unlike traditional methods of construction, you cannot “lose” discrepancies in level. We recommend the use of a plastic membrane (Visqueen, or similar) about 100 gauge to prevent moisture soaking up into your building.
Steel mesh reinforcement is a good idea, for the relatively small extra cost – steel mesh should prevent any future movement in the base.
SITING YOUR BUILDING
Q: Do I need to look at anything in particular?
A: There are several aspects to consider:
Overhanging trees, neighbour’s buildings/gutters etc may well catch you out. when looking at the “footprint” of your building on the ground.
Allow for gutters and a main up and over door will “throw” about 3’6″ and a personnel door about 3′, allow for this when positioning close to existing buildings, fences etc.
If you feel at all unsure, contact us at Hollybush Buildings for advice.
DELIVERY AND INSTALLATION
Q: Do I have to be in when you deliver and install?
A: No, you do not need to be in when we deliver, providing access to your concrete base is clear.If your base is larger than our recommendation (6″ longer and 6″ wider than the external size of your building) you need to clearly mark the required position of your building with an indelible marker)
Q: Will you drive your lorry onto my drive?
A: No, our lorry will be parked as close as possible, and the building will be delivered using a motorised fork lift.
Call Hollybush Buildings: 0800 1975046 or 01474 812876 for more information