Garden Wall Construction

[Andrew]

Why would a free-standing garden wall need a DPC ?. Even if it did, I would use some old slates as a DPC. Mortar will adhere to that.

[Bev]

Its your choice and your money. You don't have to listen to other views.

[The Natural Philosopher]

Why would you use damp coursing in a garden wall?

[Jeff Gaines]

But I would be interested to know why people feel piers are needed on a 9" wall.

[Tim Lamb]

I don't know. I have never needed to build one. I suppose one might need to consider efflorescence from wicked up moisture.

We once looked over a house some friends were considering purchasing. The garden access was by a gate set in a single brick wall. On leaving, I had to force the gate shut and realised the wall was only being kept upright by the gate post!

[alan_m]

For a 2 metre wall you may need more than 9 inches width and piers would give you this effective wider width.

A table of recommended SAFE wall heights/widths can be seen at

I'm not sure that I would like a wall 9" x 6 foot x 27 foot without some extra support along it's length.

If you already have fairly established shrubs and bushes along the boundary how difficult will it be to dig the necessary footings/foundations of the wall and having to remove roots without actually killing of those shrubs bushes.

Is there any clay heave in your area? Around my way some brick garden walls built on an estate 25 years ago are showing signs of cracking and displacement. Your wall appears to be a public access boundary!

If it was my boundary I would be considering concrete fence posts, concrete gravel boards and better quality wooden fence panels -not only for cost but for safety and personal liability reasons.

[Jeff Gaines]

Thanks for the link, that is useful :-)

It says a 1.5 brick wall can be 2175mm heigh, unfortunately it doesn't cover 2 bricks - 9". No mention of piers/pillars though.

[The Natural Philosopher]

that soon washes off, the point is what is to rot in a garden wall? Frost spalling is an issue, but mainly in the wall top. Just use quality brick on top, or put a hard cement capping on

Not unusual in very old houses

[The Natural Philosopher]

It depends on where its likely to get any lateral loads. It's basic mechanical engineering. If the vector comprising the lateral load - which might be wind - and the weight of the wall itself, falls outside the base of the wall it's putting brickwork into tension, which its not good at.

If you read my previous post the advice is to add steel ties inside the wall to tie everything together - that at least means that *parts* will not fall down - the whole shebang will go under heavy load: -)

Once you have a *reinforced* wall, the only failure mode left is that it falls over as a unit under heavy wind. The buttresses/piers/pillars extend the base and make that less likely.

I strongly advise lots of steel and really good quality hard brick /cement/proprietary capping on the top courses, and if you live in a windy spot consider a couple of buttresses...

[The Natural Philosopher]

But you will need them to put the stone lions on, surely? :-)

[alan_m]

At the bottom of the table they state 1.5 bricks is = 325mm or 12.8 inches (already more than 9 inches)

1.5 bricks is 1 brick lengthways and 1 brick sideways as shown the diagram on page 2 of This document also gives recommended foundation sizes

If you think that 2 bricks is 9 inches then you are misreading the table. 9 inches is 1 brick lengthways and your maximum safe height is more like 1300mm.

[alan_m]

Further, do you need permission/planning to dig the public side of the wall, in the access pathway, to give you the width of the necessary foundations?

[alan_m]

From what I've read today :) a DPC at the base of a free standing wall can seriously weaken it and is not usually needed. More normal is some from of DPC towards the top of the wall or below the coping stones.

[Jeff Gaines]

Many thanks :-)

I find it confusing when the width of a wall is measured in the length of a brick I'm afraid - bit like something being 4 times cheaper which, presumably, means a quarter the price.

To summarise in terms I can understand I will either need a 14" wall or a

9" wall with piers I think. It will be interesting to see what the builder suggests in his quote but I think this is probably not viable. Fortunately I do have the contact details for a good fencer :-)

Thanks to all!

[alan_m]

Double brick width wall more like 4,500 bricks. Foundations at least 2.25 cubic metres of concrete

[Andy Burns]

Poke 6 and 27 into here, then double it ..

£100/cube, or it was a couple of years ago mixed onsite.

[alan_m]

It is x4 it... The wall has to be two bricks lengthways wide (18 inches) whereas that calculator is for a wall 1 brick widthways wide (4.5 inches). Plus an allowance for breakages albeit in a two lengthwise brick wall any (cosmetic) corner damage to bricks could be hidden in the middle of the wall.

sanity check wall is 6.88 cubic metres brick with 0.4 inch mortar on 3 sides is 0.001925 cubic metres bricks required = 3575 + allowance for damage or breakages.

I originally overestimated the wall to be 2 x 9 metres instead of 1.8 x

8.22 metres.

[alan_m]

For quality tunnel and groove wood panels, concrete posts and gravel boards one of my local fence contractors would charge approx £1,000 for that fence including fitting. The price does NOT include removal of waste (old fencing) so also factor in the price of a skip.

Try their estimator

Select timber fencing and concrete posts IMPORTANT select a fence height of 1.8 metres to give the choice of 6 fence panel styles (£30 to £80 per panel). Select their installation @£360 for that length of fence You don't have to give your details on the last page - just scroll down to the breakdown of price/costs

Cheap panels will have one good side and an easily climb side. To prevent easy climbing the good side should be fitted facing the public path. More expensive panels may have two good sides and no horizontal bars to ease climbing.

[Andy Burns]

[Andy Burns]

[sorry clicked send too early]

Does it? thought the O/P wanted 9"