Defect of rising damp to slab.

Slab rising damp defect. QBIS.

Moisture meter gauge:

Although the moisture meter readings were only slightly higher than usual, this can be misleading if it has not rained for a while.

There is a high probability that the readings may increase considerably in differing weather conditions. As you can see, Visually there is a problem.

This is why you never rely upon meter readings alone to make an accurate assessment, other factors must also be taken into consideration.

Rising damp defect to a garage slab

Concrete deterioration:

As you can see in these photos the concrete surface is pitted to varying degrees from deterioration, most likely from high salt content in the soil.

Slab rising damp defect in a garage

Possible cause of problem:

Cause of the fault maybe due to the plastic membrane (fitted below the slab) may not be wrapped around edges of the slab far enough. This would not be possible to determine by a visual inspection with accuracy. Further investigation by removal of linings would be required.

This problem may require injection of a water impervious chemical barrier at regular intervals.

Rising damp defect to slab. Important points:

  • Rising damp may cause rot to the lower timber wall framing if a damp barrier has not been fitted during construction.
  • Further investigation would be highly recommended to determine if moisture barrier’s have been fitted.

Rising damp may also cause deterioration not only to the walls and possibly stored items in the garage, but may also attract termites.

Some information regarding rising damp that may be of use

Cornellengineers: Vapour barrier under a concrete slab

South Aust Gov: Membranes below slabs

QBCC Standards & Tolerances Guide

For independent Building Inspections Brisbane in all suburbs, Qld Home Buyers Inspection Service.