Apartments at this former Lancashire Mill had been experiencing water ingress issues and we tendered to Lime Repoint approximately half of the street side façade. This was a large repointing project undertaken during good weather and temperatures in the summer months.
When comparing both sections of the building, there is currently before and after showing the benefits of repointing with a pure lime-based mix upon heritage properties.
It appeared to have previously been cement rendered as the stones had become significantly deteriorated. There were patches of cement render to the stone along with cement repairs upon the headers and cills.
Cementitious mortar pointing had been carried out which required raking out. The joints were hollow behind and therefore required deep fill packing with lime. Once this had been carried out we were able to lime face point. The works were hessian sheeted, sprayed to moistened and brushed back to finish once carbonated.
Lime mortar is porous therefore allowing moisture to transmit and not to be retained. Masonry has a small level of porosity, absorbing moisture when the non-porous cement mortar prevents evaporation. As on our project, the masonry then begins to spall. We defrassed the stonework while we were progressing.
The cills and headers were stripped of the cement patches and over coated with a lithomex stone repair mortar. We will produce a separate casestudy on this process in the future.
We resealed the windows and repairs were undertaken by others to the roof and gutters, as these were other areas of potential ingress issues.
