Bricklaying & Repointing

Is it acceptable to join house and new extension with expanding foam?

Anonymous user 9 March 2024 - 2.52 PM

We have parted company with our unreliable and untrustworthy builder, who has left a single storey ground floor extension unfinished. We are now getting local tradesmen in to finish the extension and to rectify the horrors they are uncovering. Already the roof is being redone and we will need to employer a new renderer and joiner amongst others. Our neighbours on one side have now informed us that there was a gap between the extension and our existing house which the builders have filled with expanding foam and then rendered over. I can't Imagine this is good building practice but am no expert. Is this an acceptable way to do it? If not, what should have been done; how can it be rectified and what are the consequences of doing it this way in terms of damp/being watertight etc. Finally which trade should we get in to rectify it? Any advice would be greatly appreciated.