The Challenges Of Non-Traditional Housing Refurbishment
It’s estimated that some 1.5 million houses were built using non traditional materials and methods of construction between the 1940’s and the 1970’s. Without going into too much detail as you can read our article on the History Of Non-Traditional Building, non-trad house building was born out of a severe housing shortage and a post war environmental impact. There was a need for housing … and fast.
By definition, traditional house building is represented by brick or brick and block construction with a pitched, tiled roof. Solid wall popularity was overtaken by a cavity wall build from the late 1930’s. This definition would imply that non-trad construction is any other way of construction. And that’s exactly what it is!
Whilst there are hundreds of different types all non-trads be categorised within four sectors:
- Timber frame construction.
- Metal frame construction.
- Instu concrete.
- Precast concrete.
So, just what are the challenges of non-traditional housing refurbishment?
Non-Traditional Housing Refurbishment – The Specific Issues
Because non traditional building methods were designed to positively impact the sever housing shortage properties were built en-mass and mainly on behalf of local councils. Entire low rise housing estates were constructed back in the 1940’s 50’s and 60’s and then came the high rise residential block that were built from the 50’s, 60’s and into the 70’s. At the time this created modern looking estates and established new communities. How times change though!
At the time the emphasis was on the speed of build along with the cost of construction. As a result these properties were built with little regards to standard of living and were only designed as a short term fix to a major problem. Therein lies the first and most general issue – these estates still exist today and in their original state pretty much. This is in spite of the fact that many properties were supposed to have a life of 20 years in many cases! They look old fashioned and dated, they are cold in the winter and hot in the summer, they incorporate little in the way of insulation so they are difficult and expensive to efficiently heat, they are susceptible to condensation and damp and overall unpleasant places to live in.
Let’s look at the specific problems of non-trad housing refurbishment:
What Is The Construction Type
Perhaps surprisingly it is very often quite difficult to establish the actual construction type. Sure, in some cases it’s glaringly obvious, in others it’s not clear at all. That’s because many types of non-trad incorporated an internal finish and an external additional cladding. This external cladding materials can include brickwork for example, making a timber framed house look like a traditional build.
Carbonation or the presence of chlorides in the concrete can commonly cause the corrosion of steel reinforcements and corrosion of column bases (in the case of steel frame construction). Corrosion, whilst weakening the affected area, causes metal to expand and as this happens any surrounding concrete will crack. This, in turn, allows for moisture penetration causing subsequent spalling caused by freeze thaw.
In many cases wall ties have corroded, broken or are no longer fit for purpose – this can be indicated by cracking in the masonry caused by the corrosive expansion and movement as cavity walls bulge outwards. Condition of wall ties should be checked along with quality and quantity of the ties originally used.
Whilst cracking can often be caused by the effects of corrosion or even wall tie failure as explained above, these old non-trads are also prone to cracking caused by foundation movement as a result of drains, trees or subsidence over the years.
As we mentioned, non-trads were built with little regard to insulation so current levels are very often a big issue. Whilst many were constructed in a way which incorporated a cavity which may have subsequently been insulated these cavities are typically very narrow and hence any thermal benefit is minimal. That aside, the quality of any insulation needs to be checked as it is likely to be old, often damp or even saturated. It may also have bridged the cavity or failed as a result of slumping.
Age Related Issues:
These properties are more than 50 years old at best so you can expect the usual age related issues, especially when you consider that the historic materials used in the original construction may not be up to the same standards as modern materials. Seals, decay and details may allow for damp penetration and condensation. Timber frames may have rotted (especially around openings and at sole plate level) and lintels also need to be checked – condition and performance.
One very popular material used in the construction of non-trad properties (both low and high rise) is a no-fines concrete. It’s estimated to have been used n the construction of over 300,000 houses and hundreds of tower blocks. No-fines concrete is exactly that, a form of concrete which contains no fine aggregate or sand. This results in a very cheap, brittle, honeycomb type concrete. It is a porous, very weak concrete with large air pockets. It has very poor insulation properties and is very difficult to fix into. Not surprisingly, no-fines concrete is not used today.
This will impact on refurbishment options and so houses need to be checked against this list:
|Non-Traditional Dwellings – Designated Defective List|
|Ayrshire County Council||Newland||Ulster Cottage|
|Blackburn Orlit||Orlit Type I||Underdown|
|Boot Beaucrete||Orlit Type II||Unitroy|
|Boot Pier & Panel||Parkinson||Unity Type I|
|Boswell||Reema Hollow Panel||Unity Type II|
|Cornish Unit Type I||Schindler||Waller|
|Cornish Unit Type II||Smith||Wates|
|Gregory||Tarran Temporary Bungalow||Winget|
Non-Traditional Refurbishment – What To Do
There you have the challenges of non-traditional housing refurbishment but what about the solutions? Simple: Speak to Structherm!
As experts who specialise in the refurbishment on non-traditional properties (low and high rise) the Structherm team can help you every step of the way. With solutions which include the unique SEWI structural external wall insulation system (designed specifically with non-trad refurbishment in mind), we are able to specify non-trad refurb solutions that no other company can and provide the right option for your particular project. Our friendly, efficient technical team will work with you to establish the optimum design and specification from both a performance and a cost effective point of view.
Designated defective? Failed wall ties? substandard substrates? There’s usually a solution! Even if demolition is being considered there just might be a better option. Contact Us >>>
We have a long history of refurbishing non-traditional homes, working on a range of different construction types. We have worked on steel and timber frames, as well as precast concrete buildings. For more information on our non-traditional work, see our Structural EWI case studies below: