Our Timber Frame Post and Beam System

About the Timbers

All natural timbers are supplied with a sawn finish but Posts, Beams and Rafters can be be supplied with a planed all round finish. If you order timber fascia and barge boards, these will generally be smooth planed to exposed side and edge.

All Post, Beam, Bracing & Cladding timbers are supplied ‘in the white’, i.e. untreated and undecorated, ready for you to use, whatever finish you wish. If you are having an oak model it may be left untreated but for Douglas Fir models we recommend you treat it for resistance to water & UV. An example product would be Treatex Douglas Fir Protection

All other softwood framing and roofing timbers are pressure treated with Protim E406 UC2

Foundation Requirements

As with all buildings it is essential to have a sound, level foundation that is set on solid ground.

For timber frame garages, carports, stores, workshops and similar buildings, most people choose to lay a concrete slab, usually at least 150mm (6”) thick and with some steel reinforcing mesh in this.  If the building and/or the floor is to carry very heavy loads you may need to have the foundation specially engineered to comply with the requirements of your local Building Control department.

When using a Slab, we recommend that the size be 25mm greater all round than the footprint of the building. This ensures the Base Plate bolts can be installed without breaking the corners. Also the last sheet of cladding can be kicked out over the slab to guard against water ingress.

SolidLox Foundations

Sometimes it is desirable to have the floor sloping slightly, for example toward garage entrance doors so that any water that drips off vehicles can drain away.

Where a concrete slab is NOT required, e.g. if a gravel drive continues under a carport, then post base pads may be acceptable, providing these are set on a solid base. Sometimes a reinforced concrete slab may suffice, and we also offer special “Swift Plinth” concrete post bases which can be incorporated in your timber frame kit.

SolidLox Foundation Types

The required foundation type is usualy decided upon by relevant information such as soil conditions, frost heave, proximity to surrounding vegetation, landscape contour (slope of site), fresh landfill, clay, sandstone, loamy soil, water table and structural load. You should refer to your local builder for full advice on a suitable foundation type.

The Post Bases

Generally we used fixed height post bases but depending on site and other requirements we may use adjustable height post bases instead.

The post bases ensure that the bottoms of all posts are kept out of any water that may lie around. It’s OK for wood to get wet, but it must be dried out and kept well ventilated so that it does not remain damp.

Adjustable Post Bases

Adjustable Post Bases

Fixed Height Post Bases

Adjustable Post Bases

If the concrete slab or other floor slopes slightly, or if the foundations are out of level, this could cause a problem with the structure. Since all posts are the same length, if the base of any of these were not level, then there could be difficulty in levelling these up so that the beams running between them – and that have to take the roof or other structure above them – are also level.

It is also desirable to ensure that the bottoms of all posts are kept out of any water that may lie around. (It’s OK for wood to get wet, but it must be dried out and kept well ventilated so that it does not remain damp).

If there is any difference in the level of the foundations for these, the height of the base can be screwed up or down (max 50mm) so that you can get them all exactly level. At the same time, the sturdy galvanised metal base keeps the bottom of each post raised up out of any water, able to be kept dry, well aired, and damp free.

The very bottom of these post bases is then bolted down to the concrete or other foundation, to be held in position and free from any uplift forces that may occur.

General Specification

Post and Beam Garages Cutaway