Inside out

-
It has been a month and a half since I asked CIGA to explain why they thought arbitration was an acceptable option given that they had done a completely inadequate technical assessment.
In a previous blog I had documented that the problem cavity was narrower in places than the 50mm mandated by building control and the BAA certificate.
The technical manager at CIGA visited and did nothing but take photos of the building and try to verify the cavity depth. Initially he borrowed my tiny flexible measuring tape (which of course bends and so over estimates the cavity depth) and then tried to hook it on to the edge of the brick in the hole to get the size of the brick.
In another spot he used a drill bit and his thumb and subtracted the brick that he measured earlier and in both instances came up with a figure of 55mm.
I told him I didn't trust his methods as they didn't match up with my own when measuring the imperial brick which confirmed a standard imperial brick size of 110mm in depth.

That puts me in a difficult situation where it's my word again someone with "37 year experience in the industry" who's whole career involves cavities.
Of course CIGA accused me of ignoring the measurements, which I knew they would but it left me feeling a bit vulnerable as even things that I thought were objective are apparently open to interpretation.

Today I decided to take a floorboard panel up for a different reason but luckily I found a whole for the electrics in the internal wall.



As you can see the cavity is filled with rubble and very sparse CWI.


Measuring the cavity and photographing it was a bit tricky so i took a bit of wood and sawed it 50mm wide then then tried to slot it between to bricks.
I then sawed 1mm off and kept inserting it until I found a snug fit that could be photographed.
(please note this is brick to brick - as you can see the mortar protrudes into the cavity , narrowing it by a further 5mm or so)



Even a this slight angle the cavity measures at 4.63 which tallies up with my measurements from the outside.

Also noted is a brick/mortar which is solidly wedged causing a bridge between the cavities.


If this is not clear evidence a negligently installed cavity then I really don't know what more evidence I can provide.


Comments

Post a Comment

Popular posts from this blog

The controversy over Cavity Wall Insulation 'topups'

-
Image
In this article I talk about the practice and problems of topping up insulation when voids are discovered, why it is being done and the potential violations of building regulations. I can only put forwards what I have understood from public documents and personal correspondence  So I welcome corrections or clarifications from the industry on this important issue for home owners and will happily update this post to reflect any inaccurate statements. We know that 100s of topups are done every year.   From what I can gather : If the BBA have not approved these topups then the relevant local authority building control should have been notified prior to topping up as an 'off licence' use of the product.  It is not clear that the correct procedures are being followed in all cases. Background :Voids are common A void is simply an area cavity between the walls which is missing insulation.  If a void is large enough then the insulation will not be compliant with the meter square
Read more

Lintels, weep holes and render

-
Image
I found the notion of lintels in cavity trays difficult to visualise. The reason I'm looking into lintels is that there is a damp patch that runs along the lintel over the front door. Brick houses built today will have cavity trays and weep holes inserted into the design. You will spot weep holes these as either gaps in the mortar or where the mortar is replaced with a perforated plastic insert as below. CIGA state that no water should enter the cavity is properly maintained building. If that is so then why does building control mandate a cavity tray. Typical modern cavity tray with weep holes sitting on a steel lintel. The purpose of a cavity tray is to ensure moisture that gets in the cavity when driven through the mortar joints or other means is directed back to the outside wall and out of the building. If you didn't have a cavity tray or some sort of damp proof course then moisture would collect on the flat lintel and then flow off the sides of the lintel or soa
Read more

Discrepancies between Internal and external DPC (damp proof course)

-
Image
In a cavity wall construction, one would expect that the damp proof membrane to be at the same level on both walls. It turns out this is not always the case and my house is a good example where the internal wall's DPC is more than a brick lower than the external wall DPC. I didn't even think to check this before reading the CIGA Technical note 14 . This clearly states that if the distance between DPC and ground level is within a brick (as was the case with my property at time of install) then 'numerous other factors' must be assessed before declaring the dwelling as being suitable for CWI. CIGA  Technical note 14 . One of the factors is the relative level of the inner and outer leaf DPC. This is exactly what I found in my property. Ive used a floorboard to show the position of the internal floor. The DPC is clearly a brick below the floorboard and less than brick above the block paving. External leaf DPC is 1 brick below the floor level.
Read more