Why am I seeing cavity blocks?

Four Phucs Ache

I'm in the process of reviewing builders websites with regards to a kitchen/ utility extension.

The portfolio's and galleries of 5 or more builders show before during and after.

The photos show cavity blocks in each of them for the complete structure with pallets of new cavity blocks sitting in the garden. Some of the extensions are 30- 40sqm so not small.

Fair enough the photos show interior vapour barrier , studs and insulated plasterboard with a render finish outside.

Is this normal because it goes against what I believe is an old method with known issues with wide condemnation by anyone I have discussed this with.

I will be going with a fulfill cavity anyway but what I'm seeing I wasn't expecting from builders.

Metric Tensor

Still quite common in the east of the country - particularly Dublin.

Not something I'm a fan of but it has it's "fans."

There are ways of doing a "cavity-less" wall without using hollow blocks too!

Metric Tensor

Also to point out - if the pictures are not of domestic builds hollow blocks have some uses in non domestic areas where a fair faced unrendered wall of a certain thickness is required.

Schools are a classic example. The Dept of Education love hollow blocks like you wouldn't believe!!

Four Phucs Ache

They are all residential builds, they all show trench walls , slab and then cavity blocks 10 or 12 rows high with top row closed with a 4 inch block or a wide soap block.

One even shows a large RSJ sitting on a bed of concrete on a door opening instead of a special padstone.

I'm just confused as these are in the trade and are advertising that they aren't using new improved methods.

B-D-P--

Pm me the site pls.

Calahonda52

Four Phucs Ache wrote: »

They are all residential builds, they all show trench walls , slab and then cavity blocks 10 or 12 rows high with top row closed with a 4 inch block or a wide soap block.

One even shows a large RSJ sitting on a bed of concrete on a door opening instead of a special padstone.

I'm just confused as these are in the trade and are advertising that they aren't using new improved methods.

No obligation to do so so why bother: its Ireland after all

In any event, a well built cavity block wall, with all the trimmings done right can often be better that a poorly built cavity wall

Four Phucs Ache

Just to point out my issue is not with the builders themselves as the work looks spectacular when finished but the use of the cavity block when all I see and hear is 200mm full fill / pumped cavity, special cavity closers and corner details etc.

The roads are full of vans and trucks specialising in insulation improvement so why when you have a choice, invite an issue that they advertise on the vans/websites as needing improvement.

I understand attention to detail is paramount and you note a bad cavity wall is worse than a good cavity block wall which I respect.

tabby aspreme

Back in the last century when I was a young lad I spent a few summers waiting on blocklayers and back then cavity blocks were referred to as " water troughs " and they haven't improved since

Lumen

Isn't it simpler and stronger to build block on flat with external insulation? Rather than messing around with cavities. Structural elements can sit on the blocks, windows and doors can sit in the EWI layer. Continuity of insulation up and over the roof rafters. Lots of thermal mass. Stick up shelving without worry about penetrating the insulation. Job's a goodun.

(says the armchair builder)

Metric Tensor

That has quite a bit of merit Lumen.

BUT - Cavity walls developed for a reason - weather-tightness.

Nothing beats a cavity to stop moisture getting through a wall!

Of course if you pump your "cavity" full of bonded bead you don't technically have a cavity any more so you're working with a hybrid already!!