Fence Frame Installation

A frame can only be as straight as the posts underneath it. That is why most of the work happens before the first frame is even lifted off the ground.

• Setting out the line. Pegs and a taut string line mark where the fence will run. Posts are usually 2 to 3 metres apart, but the exact spacing depends on the width of the frames.
• Setting the posts. The holes are dug below the depth where the ground freezes in winter. This depth varies a lot by region, so it is worth checking what is usual where you live. The bottom of each hole is compacted, often topped with a layer of gravel, and the posts are concreted in perfectly upright.
• Letting the concrete cure. The posts must not carry any load until the concrete has hardened. The manufacturer of the concrete mix states how long this takes. Rapid-setting post mixes need less time, ordinary concrete usually needs several days.
• Fixing the frames. The frames are attached to the posts with brackets and bolts, and steel frames are sometimes welded. The work starts at the end post, and each piece is checked straight away with a spirit level and the string line.
• Tightening and infill. Once all the frames are in place, the fixings are fully tightened and the infill is fitted, unless it already comes as part of the frame.

Why check every frame separately? A small error on the first section carries over to every section after it. By the end of the line it often shows up as a visible gap or as stress in the structure.

Galvanised steel frames carry the most load and suit places where the fence catches a lot of wind or acts as a barrier. Galvanising, often with a powder coat on top, protects the steel from rust. Cutting or drilling damages this protection, so the spot needs a coat of zinc-rich paint straight away.

Aluminium frames are lighter and do not rust, so they need hardly any maintenance. They are less stiff than steel, which is why they are mostly used for decorative fences that carry less load, typically along the street side of new houses.

Frames with timber infill look natural in a garden. The metal frame carries the structure and the timber gives the look. The wood needs regular treatment and protection from moisture, otherwise it ages quickly.

Made-to-measure frames make sense on a slope, on an irregular plot or where the fence height is not standard. Standard panels would need a lot of adjusting there. A frame made to site measurements fits first time.

A level, accessible plot with soft soil and system frames of one width means quick installation. These things make the job longer and more expensive:

• A slope where the frames have to be stepped or made with angled edges
• Stony or clay soil, or a high water table
• Non-standard sizes, corners and changes of direction in the line
• Welding on site, followed by anti-corrosion treatment of the joints
• Heavy frames with solid infill that need more people or lifting equipment
• An old fence that has to be taken down first, including its footings

Before any digging, find out whether underground services run along the fence line: electricity, water, gas or telecoms cables. The utility companies can tell you where their lines are and often mark them on site. If you damage a gas pipe while digging or smell gas, leave the area and call your local gas emergency number or 112. Any repair to a gas pipe is a job for a qualified, registered gas engineer.

If the fence stands on the boundary with a neighbour or along the street, check beforehand whether it needs planning permission or a notification. Local rules often depend on the height of the fence, where it stands and the local development plan. Your local building authority can give you a reliable answer. In some areas it is also polite and sensible to agree the line of a boundary fence with your neighbour in writing.

If your posts are already firmly concreted in and the frames are bolted on with brackets, you can do the installation yourself. You will need a helper, a spirit level, a string line, a cordless drill driver and spanners. Leave any welding to a welder.

1. Check that the concrete around the posts has cured as long as the manufacturer recommends.
2. Stretch a string line along the whole fence at the height of the top edge of the frames.
3. Check each post for plumb with a spirit level and measure the spacing between them.
4. Fix the brackets to the posts at the same height, using the string line as a guide.
5. Fit the first frame at the end post and only tighten the bolts lightly for now.
6. Check the frame with the spirit level horizontally and vertically and adjust it if needed.
7. Carry on with the next frames the same way and keep checking the line against the string.
8. Once all frames are in place, tighten every bolt fully.
9. Treat every cut, drilled hole and scratch with zinc-rich paint.
10. Fit the infill if it is not part of the frame, and tension the mesh evenly so it does not ripple.

• Uneven post spacing. The frame then does not fit, or it gets forced into place under stress.
• Shallow footings. Frost gradually pushes up and tilts posts that do not go below the frost line.
• Loading fresh concrete. The post moves and can no longer be straightened.
• Checking only at the end. Small errors add up and the whole line has to be corrected.
• Untreated cuts and holes. Rust starts exactly where the zinc coating was damaged.
• Cheap fixings. Bolts that are not galvanised or stainless rust, and the joints work loose.

• The posts stand upright and do not move when you push them
• The top edge of the frames follows one line, or even steps on a slope
• The gaps between frames and posts are the same along the whole length
• All bolts are tightened and none are missing
• Cuts, holes and welds are treated against corrosion
• The infill is firmly fixed and the mesh does not ripple
• The concrete around the posts is not cracked and water runs away from the posts
• The site is tidy and the excavated soil has been removed or spread as agreed