Building Bridges in the Garden
Over a garden pool or in a rock garden or other suitable setting, well-designed bridges can look charming. Their construction need not be complicated, although strength is most important.
A bridge should look natural in its surroundings, so try to incorporate a little of the design work and material of the bridge into its surroundings. If, for example, the bridge is covered with crazy, insert a few stepping stones of crazy paving in the garden at the immediate approaches to the bridge.
An attractive bridge can be constructed entirely of wood. Make the basic supports of beams at least 6 to 9 in. square, and treat them with a good wood preservative. Stand the ends, which will rest on either bank, in a preservative for at least 24 hours to impregnate the wood thoroughly.
Cut the supports to length (that is, the length of the span plus 4 ft. so that 2 ft. can be let into the bank at each end). The supports can be retained by sinking Rawlbolts of suitable length into a bed of concrete (1 part cement to 4 parts sand).
Drill holes in the ends of the supports to take the bolts, and fasten them down securely with washers and nuts.
To surface the bridge, screw 1-1/2 in. thick planks on to the beams and at right angles to them. Use brass screws because they will not rust.
A simple handrail can be constructed for this type of bridge. Cut the upright supports for the rail from 3-in. square timber to support the rail at a height of about 3 to 3-1/2 ft. above the bridge. Allow sufficient length for them to be bolted through the supporting beams below. Space the supports not less than 3 ft. apart. The top rail should be made from timber 3 in. by 2 in., and the corners carefully planed or sanded smooth.
To provide additional strength to the handrail, bolt or screw a piece of 3-in. square timber into the bottom of the supporting beams underneath the middle of the bridge, to extend 3 ft. beyond each side. Fix a length of timber to the end of this beam and to one of the rail uprights just below the handrail; this will give triangular strength to the structure.