• A technical report on a particular problem, such as cracking or dampness
• Economical and quick
• Determines whether or not a “mountain or mole hill”
• Hough & Co. will inspect the property, focusing solely on the issue identified. The reports are tailored to identify the cause of specific issues, such as structural movement or roof defects.
• Hough & Co. will advise on any necessary repairs and provide recommendations including estimated costs if required. A full Schedule of Works and specification can also be prepared if requested. Building Pathology is what Chartered Building Surveyors find particularly rewarding. The cause of building defects may involve intrusive investigations such as trial holes, CCTV, and opening up concealed voids.
• Defect Investigation Reports require a methodical approach in order to fully evaluate each case. We have significant experience with a broad spectrum of building defects and will be delighted to discuss any issues you may have.

You may require this investigation following an unfavourable mortgage valuation, Homebuyer Survey or Building Survey.  It entails breaking one or more holes through the concrete floor slab and digging down to determine the characteristics of the slab and sub-floor fill material.   A sample may then be taken for laboratory analysis to determine the level of sulphate ions present.  The hole made is reinstated with concrete upon completion of the investigation.

Hough & Co can monitor the excavation process providing a detailed specification in accordance with current Building Regulations.  A report is also compiled upon successful completion of the replacement floor that is acceptable by financial institutions and mortgage lenders.

Why is sulphate attack a problem?

Because many mortgage lenders will limit their borrowing criteria on buildings with this defect. Typically the problem buildings are those built prior to 1965 when The Building Regulations were introduced advocating the requirement to install a suitable horizontal damp proof membrane sandwiching the concrete floor slab and the sub-floor fill material beneath.

How does it occur?

Sulphate ions migrate into the Portland cement within the mixed aggregate, sand and cement concrete mix, which chemically react when moisture is present. Moisture can occur due to a burst mains water pipe, leaking drain or raised/increased water table. This chemical reaction causes deterioration to the strength of the concrete.

What damage can it cause?

It can cause fracturing, heave or delamination of the concrete to the underside. The cement is weakened allowing separation of the mixed aggregate and sand components that will loosen. The concrete floor slab will eventually disintegrate.

What remedial work is required?

The defective concrete floor slab will require replacement. This will include excavation of the existing concrete floor slab and sub-floor fill. Reinstatement with a compacted sub-floor fill, sand blinding, insulation and a 1200 gauge horizontal damp proof membrane beneath the new concrete floor slab will be needed to comply with current Building Regulations.