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Beamlock Garage Sub-Frame

The garage frame will be of the same overall dimensions but with braces fixed only to the open beam and post joints as illustrated on the garage floor plan on page 5.


The sub-frame of treated timber that forms the support for the external cladding can now be prepared.

Start with one side first which will then need to be completed before progressing to the second side and then the rear of the garage.


The “sole” plate, which is the bottom horizontal length of timber that spans between posts, is installed first (39).

This is cut from pressure impregnated 47mm x 100mm sawn timber that is measured to length and cut to fit snugly between the shrouds on the posts, where there is no vehicle access required.

There are three lengths at 5.4m provided for the side walls and for the rear flank.

Garage Subframe Step 39 - 40 

In some applications the timber may be sited onto a dwarf wall or similar feature. Although the timber has been pre-treated for external use, it should not come into direct contact with soaked substrates or the ground. This can be prevented by applying a damp proof course (not supplied) (40) or raising the timber slightly on to supports.

The vertical uprights also use 47mm x 100mm sawn and pressure impregnated timber cut to size from 2.4m lengths. The first uprights to be installed are those that will be fixed to the posts and span between the sole plate at the bottom and the underside of the horizontal beam at the top. The wide face (100mm) of the timber should be fixed flat to the post to the outside edge (41). This is so cladding is readily accepted for fixing later and is affixed to the outer face of the post.

As the shrouds at the bottom of the posts stand proud of the posts, it will be necessary to carefully measure and cut a small section from the 47mm x 100mm upright in order that it can be fixed flush to the post (42) & (43).

The upright is secured to the post using 100mm galvanised nails for external application (provided) (44).

Garage Subframe Step 41 
 Garage Subframe Step 42 - 43  Garage Subframe Step 44

Once the post uprights have been secured in place, the intermediate uprights can be fixed. There are seven intermediate uprights for each of the two sides to be clad (45).

Measure and mark an equal distance between the Beamlock posts on each side of the garage. Measure along the sole plate on the floor and horizontal beam above, to identify the centre point of the side wall. This is where the first intermediate upright will be positioned. Measure the height between the top of the sole plate and the bottom of the beam, where the upright will be inserted.

Trim the end of the upright to this measurement and secure in place using 100mm galvanised nails provided (two to the top and two to the bottom) spiked in at an angle on either edge of the upright (46) & (47).

 Garage Subframe Step 45

Garage Subframe Step 46 - 47

In the same manner measure, mark and trim a further three intermediate uprights to be positioned on each side of the centre upright that has just been secured. This will be at approximately 600mm centres.

Note: The uprights are to be placed on the outer edge of the sole plate and beam with the wide face (100mm) facing outwards. This is so cladding is readily accepted for fixing later. Care should be taken to ensure the uprights are secured in the true vertical.

 Garage Subframe Step 48  Garage Subframe Step 49 - 50

Having secured the sole plate and the uprights into position the side wall section is now braced withdiagonal timbers of 25mm x 100mm in the pattern shown, using 65mm galvanised nails (48).

The bracing timber should be cut at the appropriate angle to butt cleanly against the post at the top and the opposite, corresponding brace at the bottom and then fixed to the inside of the frame (49).

The bracing is then nailed to the uprights where the two intersect.

Once all the sub-frame (sole plate, uprights and bracing) is secured to the garage, the sole plate can be secured to the ground by drilling through the timber (50) into the foundations and securing with M10 x 100mm anchor bolts (51).

There should be three anchor bolts spaced evenly down either side of the garage sides and two to each of the two back sole plates.

Garage Subframe Step 51 
 Garage Subframe Step 52 - 53  

The rear of the garage is different to the sides as there is an additional post in the centre of the wall. The sole plate and the uprights are cut and fixed in the same manner as previously described, however there are four intermediate uprights to each of the two sections at the rear of the garage.

The sole plate and beam should be measured and marked so that the intermediate uprights are fixed in an equal distance from each other, within each of the two rear sections at approximately 500mm centres. Cross bracing is then cut and fixed as previously described (54).

Garage Subframe Step 54 

Measure the correct overlap requirement of 125mm for the cladding around the building and mark the position as a guide on the vertical uprights, the subframe and the cladding stop to ensure a horizontal finish for the cladding.

Starting at the bottom and working up as far as the main horizontal beams, cladding can now be measured and trimmed to the correct length and nailed using 50mm galvanised nails.

Cladding is nailed to the uprights and posts, to the external face of the garage. Each piece of cladding should overlap the piece below by 25mm and should be nailed 30mm from the bottom edge. Each nail only passes through the top piece of cladding and this piece of cladding ‘pinches’ the top of the piece below.

The sections of cladding that adjoin the shrouds will need to be cut to suit, to ensure a flush finish (55).

Garage Subframe Step 55 

The finished garage should now be rigid and ready for roof preparation (56).

 Garage Subframe Step 56