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Steve_C
23rd November 2010, 08:53 AM
I am new to this forum and would like to pose a question that I am struggling with regards TG20:08 on ties.

On page 18 of volume 1 figure 1 (typical independent tied scaffold) indicates that ties should be every other lift as a minimum.

I understand this, but a number of persons involved in the new house building field keep informing me that ties are not required on a standard square box type house because the scaffold is tied at each of the 4 corners.

Could someone please clarify the matter.

Regards


Steve

biffo0911
23rd November 2010, 09:49 AM
Steve,

If you look at page 44, section 5.7.2 of TG20:08 there is a description of the 'equivalent tying value of scaffold returns and buttresses'. This does state however that the return scaffold should be tied in accordance with TG20:08.
Although it is obvious that a 4 sided standard new build scaffold cannot fully collapse due to the returns, each face of the scaffold still needs to be able to transfer the wind load (and other horizontal loads) laterally to the returns. Depending on the length of each face this may require plan bracing.
What you may need to do is get a generic design for the type of scaffold you are building and use it for all similar scaffolds.

Steve_C
23rd November 2010, 10:02 AM
Biffo0911

Many thanks for the swift reply, I shall have a look at the page you quoted when I get back in the office,

Steve

ChrisEng
24th November 2010, 08:07 AM
Hi

If the elevations are short then you can utilize the returns as a tie, but it is unlikely that it will be less than the 3m x 2 allowed for the returns = 6m.

Also the return scaffold should have the handrails fitted with double couplers to be effective.

If it is longer than 6m then a tie or plan bracing will be required to tie the center of the elevation from pulling away from the building.

Hope this helps

Chris Eng

Terry@CADS
24th November 2010, 08:33 AM
Hi Steve,

There's also some guidance on free-standing house building scaffolds on page 32 of TG20:08 that you might find helpful too.

Regards,
Terry