What is Timber Rough Cast

Having lived in a property clad in Timber Rough Cast for 10 years, I have discovered that many people "in the trade" don't know what it is. This extends to mortgage lenders and insurance providers.

Ultimately, "Timber Rough Cast" was a method used to clad a timber frame in a harder-wearing cement-based render. It is debatable whether it was specified from plan or used to upgrade timber cladding. Specifying from plan would certainly have provided a faster and less costly method to standard brick and when looking at the history of "Timber Rough Cast" buildings it would have been a contender.

Timber Rough Cast is built up in layers from the external face of the structural timber frame: 1. A thin flat material - often cement board made from asbestos.
To provide rigidity between the timber studs for the rendering processes. Alternatively, Timber Shiplap (tongue and grove) may be used. 2. A waterproof layer - bituminous sheet. Roofing felt is often used. 3. Render reinforcing - Expanded metal lath. 4. Render - sharp sand and cement.

Non-standard construction

When it comes to completing forms for building insurance, there's an area to describe what the property is constructed from. I am yet to find an insurer that lists "Timber Rough Cast", often resulting in a conversation with the insurer. The building industry considers the following "standard construction" * timber frame with brick, block or stone outer skin * brick or block inner skin with brick, block or stone outer skin * solid brick

Timber Rough Cast is the outer skin, forgoing any brick.

Mortgages

If you've ever tried to buy a property using Timber Rough Cast, the mortgage lender's reaction will vary. Some lenders refuse to lend and some surveyors will zero-value a property.

The perceived risk with Timber Rough Cast is the render is not fully waterproof and over time, water seeps through and drips on to the sole plate causing wet rot. Eventually, the sole plate will lose all structural integrity and the property may collapse.

barry bucknall