Historic moisture vapour issues resolved in this busy church hall

Hasbury Methodist Church Hall was suffering from ongoing moisture vapour problems, for several years. A new section of slab was installed to increase the hall area. No DPM was present under the existing or the new floor installation.
The floor build-up and vinyl finish deteriorated from the build-up of moisture vapour, unable to evaporate the finish. Moisture testing at the time revealed elevated readings over 85% RH. The contractor at this time did not consider vapour drive issues and re-instated the same build up and finish.

The busy church hall became unfit for purpose over the following years. The vinyl surface appeared very bumpy due to the accumulated moisture deteriorating the screed build up and vinyl adhesive layer.

Koster Aquatecnic attended in January 2019 and obtain elevated readings of 99% RH across the 150m2 area. The recommendation to remove the vinyl and the degraded screed and install Koster VAP 2000 FS moisture control layer was put forward and accepted.
The removal of the deteriorated screed revealed several issues. Patch repairs had been poorly made and infilled with a very weak concrete mix. The movement joint between the new and old slabs was not maintained, had been partially infilled when the screed poured on top. Significant cracking was observed across the floor area. The general condition of the slab was extremely poor.

Crack stabilisation was carried on the existing slab using Koster KB Pox IN and sand. The thin epoxy filled and structurally repaired the cracks. Because the slab was in such poor condition, an appropriate screed build up installed. The floor was thereafter shot blasted by the Preparation Group, Lincoln.

A coatings company then installed Koster VAP 2000 FS  to the prepared surface, to permanently manage the moisture vapour. The movement joints were honoured and filled with Koster FS-H, to mainly the vapour control layer across the area and allow the correct expansion and contraction. The VAP coating was primed with Koster VAP 06 primer to accept the final screed by the main contractor.

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