Can I use thermalite blocks to build a garden wall?

[jacklyns]

Hi all,
I need to build a garden wall to separate my property from a troublesome neighbour who delights in bringing down my garden fence and has been merrily trespassing on my property ever since. My other neighbours have advised me to build a separating wall with thermalite blocks (as he'll only bring down a fence again) between our properties. I've checked these at B&Q and it seems I'll need about 40 blocks for a wall that is 4m wide x 1m tall.
I would be so grateful if you could advise me if this is a good idea. I have read that thermalite tends to absorb water and crack once frost sets in. I really can't afford to do this time and again. Am desperate for a solution that works and will stand the test of time.
Many thanks in advance.

 

[PrenticeBoyofDerry]

If your render them maybe, but if not they will soak water up, and with no DPC even rendered could still soak water. That will cause problems come the cold weather with frost, it could blow the blocks.

 

[jacklyns]

Thanks PrenticeBoyofDerry. I don't know what rendering means, but clearly it's not as as simple as just putting the blocks up and slapping some cement to hold it together. Can you suggest an aternative? What if I use normal red bricks? Would that be more long lasting? I would prefer to do it myself rather than call a handyman.

 

[PrenticeBoyofDerry]

Furnaced bricks are fine as will be natural stone or artificial stone.
The problem is with thermalite, it's an airated block and soaks up water and frost will blow them, rendering is very much like plaster but sand and cement is used, to lay a coat over the block work this will normally protect it from the weather.

 

[jacklyns]

Thanks. You have no idea how helpful you have been. Much appreciated. Just one more question. Do you know how many bricks I would need for a wall that would be 1m in height and 4m in width?

 

[Deluks]

4 wide? You mean long? Anyway, I don't think a breeze block wall will be any harder to bring down than a proper fence, I'm not talking about fence panels held in with flimsy nails.
Either get a solid chunky fence put up. 4" posts concreted in, with 4x2 rails covered with featheredge held in with ring shank nails. You can't break that without hurting yourself or getting done for criminal damage.

or, forget the breeze and use hollow concrete blocks, filled in with concrete.

 

[noseall]

Thanks. You have no idea how helpful you have been. Much appreciated. Just one more question. Do you know how many bricks I would need for a wall that would be 1m in height and 4m in width?

A single skin structure will require about 320 bricks baring in mind that there will be a few below ground. You may need to add the odd stiffening pillar though 1m high is no great shakes.

A solid 225mm thick wall will require double the amount (obviously) but i would be inclined to finish the wall with a header course and tile crease.

 

[goody2b]

Frost resistance

The micro-cellular structure of Thermalite® gives the material protection against the effects of frost.

Independent comparative frost resistance tests have been carried out on facing bricks, common bricks and Thermalite® blocks. After 20 freeze/thaw cycles, the facing bricks were severely cracked. At 61 cycles, the Thermalite® blocks showed no signs of cracking.

http://www.heidelbergcement.com/uk/...l_information/thermalite_frost_resistance.htm

 

[jacklyns]

Thanks goody2b. I've heard so many varying opinions on the durability of thermalite blocks that I gave up half way through and put up a wire fence instead. However, I am keen to take up this option sometime in the future. Thanks for the quote. Very helpful.