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Comment by Brendan Lowen on October 24, 2011 at 19:37

Hi Benlo

Thanks for your constructive feedback!

As with all construction, if it is built correctly, it should perform correctly!

The most notable area's that would need to be addressed accordingly, as you refer would be where the bracing, or in particular, the K-bracing occurs. The Cavity Batt is supposed to fit snug into the cavity spaces and not to allow for spaces as you suggest. Typically in all other area's of the structure the space provided between the steel stud and noggin is 600 x 1200mm. Isovers Cavity Batt is made to fit snug into this space - again skill level on site determines how well the end product would perform - this would be the same with all structures.

With regards to water proofing, SANS 517 dictates what is the best fixing solutions as well as the type of fixings to be used in area's of high wind and rain, (for both coastal and inland area's) together with sufficiently protected cold-rolled steel sections, the structures have guarantee's of over 50 years as specified by steel suppliers like Arcelor Mittal.

What is now the preferred method of preventing moisture penetration whilst allowing condensation to escape, is the application of intteligent semi-permeable membranes, such as Du Pont's "Tyvek Housewrap" or Isovers "Vario" membrane.

What is great to see though is supplementary products to further increase performance in such structures. The more interest and participation in this building methodology will surely increase awareness amongst designers and the public in general - this must surely be the ultimate aim in striving for high performance structures.

Comment by Benlo Schmidt on October 24, 2011 at 19:14

 

As Architects, we have been aware of the benefits of LSF for many years, but there were a number of concerns, which prevented us from having the confidence to specify it for our clients.

I list some of them:

• Air leakage (esp. concern in areas like Cape Town during winter storms)
• Waterproofing of facades (once again -the driving-rain we experience in Cape Town is a huge challenge)
• Rigidity of the structure, especially in high wind-conditions (e.g. the Summer south-easter in Cape Town -which seems to increase in strength every year)
• Durability of the structure in terms of corrosion due to negligent or accidental exposure of metal or due to condensation on the inside of building envelopes used to clad over the LSF.
• Effective Insulation of LSF. We have yet to see a practical application, where cavity-batts had been installed without gaps causing Thermal Bridging - especially if the design of the steel is complicated with many triangulated frames, or if there is services around which needs to be cut without gaps.

BUT . . . I am glad to be able to say with confidence, that we now have a solution for ALL of the above problems, and with some additional unique benefits.

As an example: There is a relatively simple method in which the 'racking strength' of light structures can be increased by up to 300%.

As Architects we are taking a radical turn toward advanced solutions like LSF, but it would be great to network about these solutions we have found and maybe some we are not aware of yet. Possibly even get some comment on designs we are busy working on?

Feel free to contact us at info@insuseal.co.za about what we can offer, and how we can possibly incorporate your products into our designs.

Comment by Servaas de Kock on August 3, 2011 at 18:28

This Company has the most advanced kind of these buildings in the world - http://www.dnd-frb.com/. Please have a look at their full range of different types of buildings and solutions. I think this is an unique solutions also for South Africa.

If interested or for more info, please feel free to contact me at sdekock@iafrica.com or 082 4525565.

 

Regards,

Servaas de Kock

Comment by Brendan Lowen on July 26, 2011 at 7:45

Ok, let me refer you to the SASFA website www.sasfa.co.za, have a look under Membership and find a contractor/builder in KZN... I would advise you to give one of them a call and discuss from a cost perspective in more detail. They would be in the best position to help you determine how cost effective the structures can be built to your requirements... Hope this helps, in the mean time subscribe to Advanced Building where I try to stay in touch with the latest developments in lightweight construction and fibre cement...

Comment by Swelihle on July 26, 2011 at 0:15

I am based at Northen KwaZulu Natal, Ladysmith and surrounding areas

Comment by Brendan Lowen on July 25, 2011 at 22:12

Hi Swelihle

To be quite honest - it would depend on a number of factors. I must mention though that there is a falicy that LSF construction is very cheap, this is not true, it is probably on a par with conventional construction. The savings are in the speed of construction (up to 40% quicker) but far more importantly, the performance of the structure. It is here that the life cycle cost of the structure begins to kick in. Energy costs are significantly reduced with adequate building materials that are incorporated into the structure such as a previous article I have posted on "Sustainability".

I know this does not answer your question but I will mention that in comparrison to conventional construction, the performance of an LSF structure built in accordance to SANS 517 (LSF building code) will be of a higher standard than a conventional brick and mortar house with regards to energy efficiency.

Which region are you based?

 

 

Comment by Swelihle on July 25, 2011 at 17:41

Been having a keen interest on this topic, what are typical cost of a 100sqm township house with a 80sqm first floor