B&Q Online: From Kitchens & Bathrooms to Sheds & Paving; plus planning tools

How to build a fence

Build a fence

The secret to a successful panel fence is in the preparation.

Erecting a panel fence

Bear in mind that this project is hard work and you'll find it a lot easier if you have at least one helper. Clear away vegetation and pot any shrubs or plants that you will want to replant once the fence is up. Prefabricated fence panels come in a standard 1.83m width and are generally available in four heights (900mm, 1.2m, 1.52m and 1.83m).

Fencing

1 Drill six evenly spaced pilot holes into the batten framing of the panel on both sides and at each end. Raise the panel 50mm - 75mm above the ground, this gap will help prevent it rotting from the bottom up.

Fencing

2 Lay a spirit level on the panel to check it is level, then nail it to the post with galvanised nails through the pilot holes. The top of the panel should be a consistent distance (at least 25mm) below the top of the post.

Fencing

3 Attach the second panel to the post, using temporary props to keep the fence vertical. Continue working this way until all the panels are in place.

Fencing

4 Make sure each post is touching both builder's lines, and check that it is vertical using a spirit level. Fill the post hole to just above ground level with concrete. Smooth the surface downwards so that rainwater will drain away from the wood.

Fencing

5 Soak the post caps in a bucket of water – this will help prevent splitting as you nail them on. Apply a siliconebased sealant to the underside to reduce the chance of water seeping beneath and rotting the top of the post and then nail a post cap to the top of each post.

Gravel board

Gravel boards are specially treated timbers that are fitted horizontally at the base of a fence. They protect the fence panels from rot by raising them off the ground. A rotten gravel board is much easier to replace than an entire fence panel. To fit gravel boards as you build a panel fence, leave a 150mm gap below the panels. Measure and cut 25mm-thick boards to fit between the posts. Fix them with galvanised screws or nails inserted at an angle into the posts. Countersink screws or drill pilot holes for nails.

Fencing on a slope

To erect a panel fence on a slope, you still need to fix the posts vertically and the panels horizontally, as you would on flat ground, but you should step the fence panels to match the gradient. Remember when ordering materials that longer posts will be required to compensate for the stepped panels. If you can, try and keep the steps even, if necessary digging out or building up the ground beneath to ensure the triangular gap below each section is roughly equal. Fill this gap with a length of gravel board, which is easily cut to fit.

back to top

Erecting a closeboard fence

A closeboard fence is a popular alternative to panel fencing. Featheredge boards, tapered on one edge, are nailed to horizontal arris rails which are secured to the fence posts. This kind of fence is very good for privacy and security but can be quite expensive.

Some fence posts come with ready-made slots (housings) for the triangular arris rails; others will need to be notched prior to installation. Use three arris rails for a fence over 1.2m high; two for anything lower. Make sure each post is the right way round: the back of the fence is the side where the arris rail is visible. The distance between posts should be half the length of your arris rail sections, less 50mm (cut this off each rail). Remember to position the posts on your side of the boundary.

Erecting posts

Posts

1 Put the first three posts in their holes and prop each one up with temporary supports. Insert one end of the upper arris rail into the notch of the first post and the other end into the third post. Check the arris rail is level and mark and saw off any excess: the end of the rail should reach exactly half-way across the third post. Nail it in place using 75mm galvanised nails and fit the lower arris rail in the same way. Keep checking both are level.

Posts

2 The joins in the arris rail sections need to be staggered for added strength. Therefore measure and cut the central arris rail to the distance from the outer edge of the first post to the midpoint of the second.

Posts

3 Nail the central arris rail into position using galvanised nails. The next section of the central arris rail should be a standard two-post width.

Posts

4 As well as making sure each post touches your builder's lines, keep using a spirit level to check the fence is vertical and level.

Posts

5 Continue fitting posts and rails to create your skeleton fence, supporting it with timber props as you go. Checking again that each post is vertical, concrete them into the ground and leave to set for 48 hours. Slope the concrete away from the post to drain off rainwater.

Posts

6 Fit gravel boards horizontally to the front of the posts across the base of the fence. Drill pilot holes for the nails before attaching the board to prevent the wood from splitting.

back to top

Attaching the boards

1 Using 50mm galvanised nails, nail the centre of the first board to the upper arris rail. Check the board is vertical before nailing it to the bottom rail and finally the central rail. Make a spacer by cutting an off-cut of timber to 20mm less than the width of a featheredge board. Align this to the thicker edge of the first board. Butt the second board up agaisnt it and fiz it in the same way.

2 Continue fitting boards, using the spacer to maintain an identical overlap between them and checking that each is vertical with a spirit level. When you are six boards from the last post, measure how much space you have left and increase or decrease the overlap of the last few boards so that you meet the outer edge of the post neatly.

3 Run the capping strip across the top of the featheredge boards. Nail it in place using galvanised nails. If you find the wood is splitting, drill pilot holes before nailing.

back to top

Galvanised Brackets

1 Another method of building a closeboard fence is to fix the arris rails in palce using specially made galvanised brackets. These allow you to use standard fence posts without needing to cut mortises to hold the arris rails.

2 The brackets come ready-drilled with holes for nailing them in place. End brackets have additional flanges through which they are nailed to posts. These brackets are also ideal for reinforcing a broken arris rail.

back to top