Pier caps and wall coping: how to measure your pillars and walls and choose the right size

To size a pier cap or a wall coping, start from the finished pillar or wall, not the bare masonry. A pillar measured before cladding, a single side measured, or a cap ordered to the exact size of the pillar with no overhang can all lead to the wrong size. Here is the order in which to do it, so that you can check the sizes before you order.

What caps and coping are for

A pier cap sits on top of a gate pillar or fence pier. Wall coping runs along the top of a garden or boundary wall between the pillars. Both have the same job: to help shed rainwater beyond the faces of the masonry, so that water does not sit on the top, soak into the joints and freeze.

Masonry detailing guidance recommends the same. Technical Note 36A from the Brick Industry Association, a US industry body, which is guidance rather than a UK regulation, recommends that copings overhang the wall on both sides, that the top is sloped, and that a drip is provided whatever the material (on concrete, for example, a groove underneath that breaks the line of water), with the inner lip of the drip at least 25 mm from the face of the wall. The same note adds that the fewer joints a coping has, the more reliably it keeps water out (BIA, Technical Notes 36A, rev. 1981, reissued 2001).

The 25 mm refers to the position of the drip, not to the total overhang. Whether a particular Ristone cap or coping has a drip, and where, is checked for the model you choose.

Step 1: measure the finished pillar or wall

“Finished” means the pillar or wall as it will look when complete: rendered, clad with stone veneer or clad with brick slips. That is the outline the cap or coping has to cover.

• If the cladding is already on, measure directly over it, at the top, where the cap will sit.
• If the cladding goes on after you order, measure the bare masonry and add the cladding thickness plus the adhesive layer to each face. If opposite faces have different build-ups, add them separately for each direction.
• Measure both sides of each pillar and write both down. A “400 mm” pillar might measure 390 × 410 mm.
• If you have many pillars, measure each one and note how many pillars you have for each pair of dimensions.

For walls, measure the finished thickness at the top, and the length of each section between the finished faces of the pillars.

Step 2: add the overhang

Ristone gives a guide overhang of 30–50 mm on each side of the finished pillar or wall, where the shape of the piece allows it. The exact figure depends on the geometry of the cap, the size of the pillar and how it is installed, and is confirmed with the quotation. For a centred cap with equal overhangs:

cap size = finished pillar size + 2 × overhang

coping width = finished wall thickness + 2 × overhang

With 30 mm per side you add 60 mm; with 50 mm per side, 100 mm. The range between the two is where you look for a standard size.

Step 3: check against the available sizes

The range published by Ristone includes four-way (pyramid-topped) pier caps in square sizes from 250 × 250 to 600 × 600 mm, in 50 mm steps, plus rectangular caps for pillars that are not square. Three-way coping comes in widths of 250 to 500 mm, in 50 mm steps, and straight coping in 200 to 450 mm, also in 50 mm steps; all coping pieces are 500 mm long. Current availability and colours are confirmed with each quotation.

Worked examples, all on the finished pillar or wall:

Finished pillar or wall	Range with 30–50 mm per side	Size to check	Resulting overhang
Pillar 400 × 400 mm	460–500 mm	Cap 500 × 500	50 mm per side
Pillar 420 × 420 mm	480–520 mm	Cap 500 × 500	40 mm per side
Pillar 360 × 360 mm	420–460 mm	Cap 450 × 450	45 mm per side
Wall 250 mm	310–350 mm	Coping 350	50 mm per side
Wall 300 mm	360–400 mm	Coping 400	50 mm per side

For a rectangular pillar, check each direction separately. On a 300 × 400 mm pillar, a 350 × 500 mm cap looks close, but on the short side it overhangs only 25 mm, below the guide range. A 400 × 500 mm cap gives 50 mm on every side.

If a much larger cap is chosen than the pillar needs, bearing, fixing and proportions have to be checked. A cap that is too small may shed water less effectively beyond the face of the pillar.

Step 4: count coping pieces per wall section

Each coping piece is 500 mm long. A first estimate for one section is its length divided by 500, rounded up. That estimate ignores the joints between pieces and the gaps at each end.

The length of a section splits into: the pieces + the joints between them + the gaps at both ends. With n pieces there are n − 1 joints. Joint width and end gaps depend on the product and the installation, so they are agreed before the cut lengths are worked out. On a 1,500 mm section, three whole pieces already make 1,500 mm before any joints: the total length of the pieces has to be reduced by the combined joint widths and end gaps; agree with Ristone and the installer how the cuts are distributed.

Send the length of every section rather than one total. Ask whether suitable offcuts can be reused in the agreed cutting layout; that may reduce the number of pieces to buy.

Not finding your size

This happens with old pillars, heavily clad pillars or very wide gate piers. Ristone also produces non-standard four-way caps, but only in sizes already in production, not any size to order. Send the finished dimensions of each pillar and Ristone checks whether a piece fits.

Delivery to the UK and the rest of Europe

Ristone manufactures in Romania and supplies the UK and the rest of Europe on a quotation basis, depending on product, quantity and destination. For the UK, transport, customs duties and import VAT are paid by the buyer. Ask for the delivered cost before you confirm the order.

What to send with your enquiry

1. the finished dimensions of each pillar (both sides), or the number of pillars for each size;
2. the finished thickness of the wall and the length of each section between pillars;
3. cap profile (four-way) and outline (square or rectangular), coping type (three-way or straight) and colour;
4. the delivery address or postcode and the date you need the materials on site.

Every calculation is indicative until Ristone confirms sizes, quantities, availability and transport. See concrete pier caps and coping stones, or send your project enquiry.