Building Regulations -
Your Garden Walls

Better to be Safe...

The Building Regulations do not apply to the construction of free-standing garden walls though if a wall acts as a retaining wall and is within 12 feet of the highway and higher than 4'6" then details would need to be approved by the Council's Highways department.

Garden and boundary walls should be inspected from time to time to see if any repairs are necessary or whether a wall needs re-building.

Such walls are amongst the most common forms of masonry to suffer collapse and they are unfortunately one of the commonest causes of deaths by falling masonry. Your insurance's may not cover you if the wall has been neglected. Beside the general deterioration and ageing of a masonry wall over the years walls may be effected by:

An increase wind load or driving rain if a nearby building is taken down or a protective tree screen removed.
Felling of nearby mature trees or planting the new trees close to the wall.
Changes leading to a greater risk of damage from traffic.
Alterations and additions to the wall or removal of part of the wall e.g. for a new gateway.

Garden Wall

Things to check

Is the surface of the brickwork crumbling away? If restricted to a few bricks this may not be serious but walls can be weakened by general crumbling across either face.
Is the mortar pointing in good condition? If the hard surface layer can be picked out from the joint or if the mortar can easily be scraped out with, say, a door key, then this is a good indication that the wall may need re-pointing.
Is there a tree near the wall? As trees mature there is a risk of the wall being damaged by the roots and from windblown branches. Damaged sections may have to be re-built, perhaps with 'bridges' incorporated to carry the wall over the roots. The removal of large trees can also lead to problems because the soil accumulates more moisture and expands.
Is the wall upright? Walls lean for a variety of reasons, due for example to failure below ground caused by tree roots, a cracked drain, frost damage to the foundations or inadequate foundations in the first place. If your wall leans to an extent that could present danger e.g. more than 30mm for a half brick wall, 70mm for a single brick wall, or 100mm for a brick-and-a-half wall it is recommended that expert advice is sought. This may involve checking the wall foundations.
Is the wall thick enough for its height? The table below gives guidance on how high walls should be relative to their thickness. You should seek expert advice if your wall exceeds the recommended height or in circumstances whereby this guidance is inapplicable e.g. walls incorporating piers, or walls supporting heavy gates or retaining soil.

Wall Thickness

Maximum Height

Half Brick

525mm

One Brick

1450mm

One & a Half Brick

2400mm

100mm Block

450mm

200mm Block

1050mm

300mm Block

2000mm

* HALF BRICK = 100MM ONE BRICK = 215MM ONE & A HALF BRICK - 325mm
Some climbing plants, like ivy, can damage walls if growth is unchecked. Consider cutting them back and supporting re-growth clear of the wall.
Is the top of the wall firmly attached? Brick cappings or concrete copings may be loose or there may be horizontal cracks (frost damage) in the brickwork a few courses down. Loose or damaged masonry near the top of the wall will need to be re-built and should include a damp-proof course.
Has the wall been damaged by traffic? Minor scratch marks or scoring of the surface may obscure more significant cracks. Piers at vehicular entrances may have been dislodged by impact and be unsafe. In such cases they should be re-built.
Are there any cracks in the wall? Hairline cracks 0-2mm across are common in walls and may not indicate serious problems, for wider cracks seek expert advice; some may indicate a need for partial or complete re-building. Seek advice on any horizontal cracks that pass right through a wall or any cracks close to piers or gates. Re-pointing of cracks can lead to problems. Do not re-point without establishing the cause of the cracking.

The Council under the London Building Act has the power to deal with walls that are within a dangerous condition so if you are concerned about a wall near where you live please do not hesitate to contact the Building Control service.

Building Regulations - Your Garden Walls

Better to be Safe...

Things to check

than Sorry...

Building Regulations -
Your Garden Walls