The Woolaway is a non traditionally built property from a company by the name of W Woolaway & Sons Ltd who were based in Devon.
There were two types of property built:
- The Woolaway house which were constructed between 1946 and 1956. These were two storey semi-detached or terraced properties.
- The Woolaway bungalow which were built from 1953 onwards and were all detached properties.
Any potential refurbishment program needs to be carefully considered as these are a property type that are on the official Designated Defective list as per BRE and the Housing Defects Act 1984.
By BRE report
4 foot by 2 foot pre-cast aerated contrete panels were then bolted externally to the frame with 6 bolts per panel. These panels were just 2 inches thick but were finished externally with a thick coat render system.
The roof was of medium pitch, timber rafters and finished with tiles.
The bungalows were constructed in similar fashion although externally they appear different as the external walls are a faily narrow pre-cast concrete panel and they feature a contratsting cladding finish to the gable apex.
Areas of Concern
As we said earlier, Woolaway houses are on the list of Designated Defective properties. Although the bungalows do not appear on this list the areas of concern are similar.
Always start with a full structural survey. Particular attention needs to be paid to the following three areas:
- Cracking to the pre-cast concrete columns along with the degree of carbonation and levels of chloride.
- The condition of the pre-cast concrete panels behind the render finish – paying particular attention to any cracking
- Corrosion of the 6 fixing bolts to each panel
The nature of the construction of the pre-cast concrete columns lends itself to high rates of carbonation and low levels of chloride which, in turn, corrodes the rebar hence causing the concrete to spall.
Being Designated Defective means that structural survey is vital. The condition of the concrete frame is of paramount importance to any refurbishment program. Cracking to the infil panels can also cause issues which is why Structherm have, in the past, specified the unique Structural External Wall Insulation System or SEWI for short. You can read more about the SEWI system here.
Any localised repairs to the pre-cast concrete frame need to be first carried out. The inulated SEWI panels can then be installed. The benefits of using the structural EWI system is the fact that the panels will span from column to column. Therefore, once all localsied column repairs have been carried out it can be installed. The condition of the panels doesn’t matter as they’re spanned and not required as fixing points like they would be if utilisng a standard EWI system. These panels can therefore be either left in-situ of removed. Woolaway Refurbishment Case Study >>>.