Design of timber scaffold boards - TG20:08 (1 Viewer)

Georgina Molloy

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Hi All,

Can anyone tell me if the 'working moment of resistance' of timber scaffold boards in table 18 of TG20:08 should be compared with factored loads?

Design of other scaffolding components (tubes, couplers etc) is based on safe load capacities (factor of safety included in capacity given) but I believe that the timber board strengths have no safety factor included...am I correct????

Thanks a million.
GM
 
Georgina,

You need to look in BS 2482-1:2009. 38mm/1.20m span:

Page 19: working moment of resistance = 0.50 N/mm2
Page 22: Ultimate moment to be achieved in test = 0.90 N/mm2 (5th %ile)

Therefore factor of safety on working moment of resistance is 1.8:1.

You could use the minimum ultimate moment, that would give you 1.54:1.

Ben.
 
Laminated Scaffold Boards are the future , scaffolding is engineered and designed to meet certain codes. You can never guarantee a Softwood Board machine or visual graded they last 5 minutes and the bands cut the scaffs hand's they are old hat and should be outlawed.
 
Thanks all for the info,

and yes with regard to grading and banding of boards, quality seems to be a problem. I spoke to a scaffolder who got a large delivery of boards not long ago and a hugh percentage were not even banded.
 
Laminated Scaffold Boards are the future , scaffolding is engineered and designed to meet certain codes. You can never guarantee a Softwood Board machine or visual graded they last 5 minutes and the bands cut the scaffs hand's they are old hat and should be outlawed.

I have been purchasing and using LVL's for 3 or 4 years now and find them much better than softwood, they appear to be much more durable.
However this is in a dry climate, now sure how they would hold up under UK wet conditions. I sent a few thousand across earlier this year to see how they do, fingers crossed!!!!
regards
Alan
 
ive never even heard of them
what is the weight of these Alan?
cost etc?


i wonder what we will end up calling them in the UK?

Morning Jackdan
LVL is Laminated Veneer Lumber, basically it's 1 1/2"" ply cut into boards and it is widley used around the world as scaffold boards.
No warping or splitting no bands, plates, hoops etc. A very solid board which I have been using for the last three or four years without problems (touch wood, if you'll excuse the pun)

They are a heaver board than a dry softwood but then you dont find many dry boards in the UK so comparrable with a wet board. I dont expect to see too many guys claiming to carry 10 at once though.

When I first looked at them I gave it the basic test, suports at 12ft apart then 4 fat ******** in the middle, big sag but no break.

regards
Alan
 
Bending capacity of a board = 0.48 kNm
Assuming a central point load on a board spanning 1.20m, Bending in the board = WL/4
0.48kNm = W x 1.20m / 4
W = (0.48 x 4)/1.20
W = 1.60kN

Correct!
 
Bad Boy

I found this Machine Graded board on a job, It was from of a new delivery,

It was 13ft long. I suspected it had been used for Fork lift duties?

But if you look closer, there are only about 8 growth rings per inch

I thought it should be nearer 25 rings per inch? don't quote me. However, there

are knots on both sides and the board was very light. so check all boards. MG or

VG, see my albums for more pics.
 

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Some salesman or other posted a warning about this a couple of weeks back. The very next day a client called me to tell me to strike a job but be careful as there was a board ready to snap. It was a new board on a perfectly trannied job and looked very similar to you picture toppers. Seems the guy might have a point.
 
Boards are entering the UK direct from the Mills, Germany, Austria, Latvia & Czech. The Mills do not put all of the Boards through the grading machine.

They put a band on the end and hope for the best, and in this instance a board has been broken, if they are allowed to get away with this it could be a life.

Name and shame the supplier Toppers, it has to stop these companies put money before safety and lives.
 
Mmm, how about alerting your supplier first to give him a chance to investigate before slinging mud.
 
It isn't about slinging mud until suppliers take this serious they will continue to compromise quality for price, but the problem is this means life !!!
 
I have yet to meet a supplier who wouldn't look into any complaint made about their gear, especially the reputable one's. We know someone could get hurt, that's why we are talking about it and for me the first step should be the supplier then come back if a resolution is not found and everyone would know to give him a wide berth. If every mistake was punished and promoted on the internet we would all still be living in caves.
 
Before this all gets out of hand, lets see how many other companies are having the same

issue with their boards.

Could it be a one off?
 
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