Waterproofing by AB Conservatories Ltd
See some examples of waterproofing by AB Conservatories Ltd - trading as AB Conservatories - based in Tadley, Hampshire is owned by Andy Brown (not to be confused with any similar sounding companies).
The conservatory roof was placed on top of the cavity wall and secured to the bricks. A band of mortar was then slapped in the gap between the roof and the top of the wall as seen in the photos above and below.
Building Control were not happy with this solution as water could ingress through the mortar and into the cavity wall leading to damp. They would not approve this build unless this was remedied. The three solutions available were to squirt a load of waterproof mastic to seal the gap (which was over 10mm wide), fit a plastic sill under the roof or use lead flashings. Unfortunately, to fit a plastic sill or use lead flashings would require the roof to be lifted... In my opinion the mortar also looked unsightly, but decide for yourself.
Building Control were not happy with this solution as water could ingress through the mortar and into the cavity wall leading to damp. They would not approve this build unless this was remedied. The three solutions available were to squirt a load of waterproof mastic to seal the gap (which was over 10mm wide), fit a plastic sill under the roof or use lead flashings. Unfortunately, to fit a plastic sill or use lead flashings would require the roof to be lifted... In my opinion the mortar also looked unsightly, but decide for yourself.
Unsightly and potentially ineffective mortaring by AB Conservatories Ltd. Building Control did not approve this method.
The Solution - Fit a Plastic Sill
The roof had to be removed to remedy numerous faults, including : box gutter support, electrics, guttering, unsafe fasteners and un-level windows. The obvious choice was to use plastic sills and the finished product is shown below. It's totally waterproof and looks fantastic.
Our contractor fitted a PVC Sill on top of the wall to stop all water ingress.