Cavity wall tie survey

Right. Hoping for some help as quite confused. We are buying a house and the surveyor has suggested getting wall ties checked as the building is constructed of black ash mortar which can corrode wall ties and we need to assess current condition.

Had a building contractor round who states the building is NOT constructed of black ash mortar - therefore maybe not a problem. Surveyor is adamant that it is. Added to this, the building contractor says to assess state of wall ties you need to take a brick out of the wall. However, the 2 larger/well known companies inc jj crump, who are well recommended on this forum elsewhere, say it can be assessed by drilling holes and using a borescope.

 

Do I assume my building contractor doesn't know his stuff and get a surveyor round to drill holes anyway and test or does anyone know of a reliable contractor who could tell me if it really is black ash mortar and whether it's worth having a survey done?

I'm not an expert, but Sunday Telegraph's columnist Jeff Howell (who seems eminently sensible on most subjects) says:

 

"Anyone thinking of having cavity wall insulation installed should first have the condition of their home's wall ties assessed using the method described in BRE Digest 401, which specifies that two bricks should be removed on each elevation (at high and low levels) and tested for corrosion. Inspecting ties by drilling a hole in the outer leaf and looking through a boroscope is not a satisfactory way of assessing their condition, as the most serious corrosion is likely to be where the ties are embedded in the mortar."

 

http://www.askjeff.co.uk/cavity.html

how old is the property . In the year 1970 onwards a mortar was used that was coloured black for cosmetic purposes this was just a dye they put in the mortar . the bricklayers hated it There is nothing wrong with this type of mortar EX Bricklayer

Get in touch with these guys. They've just done our house and know their stuff.

 

http://higginbottom-lascelles.co.uk/wallties.aspx

 

We found them to give very honest advice and only did work that was required.