Bead filled wide cavity

moldy_sea

Could someone explain how a masonry cavity wall fully filled with bead insulation prevents water reaching the internal leaf? Are they always combined with waterproof renders?

BryanF

Read around the forum. Bead is an excepted form of cavity filling. Standard mortar render is fine

moldy_sea

BryanF wrote: »

Read around the forum. Bead is an excepted form of cavity filling. Standard mortar render is fine

Would a brick outer be also accepted?

There is a lot of cruft to read through, difficult to find gems. Though I'm sure people are tired of repeating themselves too, understandable.

Calahonda52

moldy_sea wrote: »

Would a brick outer be also accepted?

There is a lot of cruft to read through, difficult to find gems. Though I'm sure people are tired of repeating themselves too, understandable.

Will need engineering design signoff if wide cavity, especially if brick outside layer

moldy_sea

moldy_sea wrote: »

Would a brick outer be also accepted?

There is a lot of cruft to read through, difficult to find gems. Though I'm sure people are tired of repeating themselves too, understandable.

From NSAI Agrement certificate for one of the products....

"Cavity walls with the outer leaf
constructed using unrendered (fair-faced) block
work are not suitable for full-fill cavity wall
insulation. They are therefore not approved by
this Certificate."


"In normal exposure areas the types of outer
leaf masonry finishes where the XXXXX Cavity
Wall Insulation System is suitable are as follows:

 Impervious cladding and rendered walls with a
minimum cavity width of 40 mm and up to
12m in height, and
 Fair faced unrendered brickwork with tooled
flush joints up to two storeys in height with a
minimum cavity width of 40 mm.
 Walls must be in a good state of repair with
no evidence of frost damage. Mortar joints
must not show evidence of damage which
would cause water ingress."

---

So if your mum was using bead fill and wanted a brick outer would you try and talk her out of it and use a block and render instead?

BryanF

So your mum is building the house. And you want to know can she have a bead cavity fill with a brick outer leaf?

moldy_sea

BryanF wrote: »

So your mum is building the house. And you want to know can she have a bead cavity fill with a brick outer leaf?

Eh no, it was an expression. But your question is correct. And a follow on would be if you would you recommend block and render over brick as an outer?

BryanF

Block & render with beads

Gileadi

moldy_sea wrote: »

From NSAI Agrement certificate for one of the products....


 Fair faced unrendered brickwork with tooled
flush joints up to two storeys in height with a
minimum cavity width of 40 mm.


---

So if your mum was using bead fill and wanted a brick outer would you try and talk her out of it and use a block and render instead?

The bit I've left from the NSAI cert would allow for a brick outer leaf (if the correct mortar finish is used) if that was your preference. Assuming the property is max 2 storey.

Metric Tensor

Gileadi wrote: »

The bit I've left from the NSAI cert would allow for a brick outer leaf (if the correct mortar finish is used) if that was your preference. Assuming the property is max 2 storey.

Only in certain areas of the country with lower exposure. There will be a map in the middle of the agrement cert.