concrete block garden wall advice

[bitsandbobs]

Hi there

Wondered if anyone could help. The neighbours at the back of the garden are currently building a wall out of concrete block which is 100mm thick. The wall goes round three sides of their garden. The wall that is backing on to my garden is 2.08m high and looks like it is built on a concrete base. They are not planning as far as I am aware of rendering the blocks on my side (not sure what they will do on their side).

Can anyone tell me:

a) Is the concrete base a sufficient foundation
b) Will the blocks stand all round weather without rendering

Talking to their builder the intention is eventually for the wall to become part of a log cabin?

Don't want to cause unnecessary problems with neighbours but just want to make sure if it is safe. The wall is unsightly from our side but my prime concern at the moment is safety.

Many thanks

 

[theoldun]

For a decent answer, need the following.
Is it on a concrete slab or excavated concrete foundation?
If foundation, do you know depth and width?
Width of wall across your rear garden.
What piers are being built in?
Width, depth and centres of piers?
Note. Should only be 2000 high with out planning.
Concrete blocks will stand all round weather without rendering
oldun

 

[bitsandbobs]

Dear Oldun

The base is a concrete slab as opposed to excavated. The concrete base that goes across the back of my adjoining neighbour was there previously but the wall at the part at the back of my garden I think it has just been laid.

The wall across the back of my garden is just over 3.5m with the same again estimated across the back of my neighbours so total length of wall in excess of 6m . There are no piers. At the corners the block are laid flat to provide strengthening.

Should clarify the blocks aren't solid concrete they appear to be the aerated variety. A layman like myself would say breeze block.

Sorry if this is still a bit vague.

Many thanks for your help

 

[Static]

Well if it is just 100mm block with no piers then a good storm may cause it to move/crack.. even a 215mm wide wall at 2m high is pushing it..

 

[theoldun]

England and Wales are divided into 4 zones for brick walls. Zone 1 is roughly a line from Birmingham to Gt Yarmouth, and from Birmingham to say Southampton. Zone 1 is the most lax with it’s requirements, and as you go further east and north so the requirements are more stringent.
We list below the recommendations of 95% of councils in zone 1.
Half brick or 100mm blockwork walls should have foundations of at least 375mm in width, bearing onto a firm substratum.  Piers should be provided at centres not exceeding 2 metres.  The maximum height should not exceed 725mm (525mm on exposed sites).
We now list below the recommendations for 100mm free standing block walling all as BRE Good Building Guide GBG19.
Zone 1 A single skin 100mm block wall can only be built to a height of 2000 in a 550 deep by 1450 long stagger or to a height of 1825 in sheltered location as a 550 deep chevron, or to a height of 2500 (subject to planning) as a 440mm diaphragm wall. Block density to all above to be 1500kg/m3, block strength to be 10 N/m2. Foundations to be 750 wide and min 600 deep.
If DPC required, then 2 course Staff blues.
Now that lot means nothing to you, except to say that neighbours wall as built does not comply to any Good Building Practice or BRE Good Building Guide.
What can you do about it. Nothing, as none of it is enforceable, if under 2000 high.
Your only chance could be to complain to BC and the Council Environment Dept that you consider it is a dangerous structure. Say for your grandchildren, pet tortoise, dog etc
From description of blocks, would say they are not dense concrete, but med weight aggregate with open texture face, something like Fibrelite or similar. Come winter, with some rain and frost, they will start spalling and blowing. Not your problem.
If wall looks ugly, ask neighbour if he going to render it. If not throw a 2000 high fence along it.
As built wall coukd stand up next 50 years, but then again good wind this winter and she could go over. Our money would be on the later.
oldun

 

[^woody^]

The answers to a and b are both yes.

And when a log cabin is formed, the roof will brace the walls

Your post suggests that you are more concerned with aesthetics and perhaps citing safety as a lever to get the wall altered.

You can't do anything about it except try and mask the wall