Shoring CMU walls 1

[kmead]

Hi,
I would like to know if needling is a good method of shoring CMU walls, or if there are any other proven methods? Also, what is typically used for needling? I.e. tubes, wide flanges, pipes?
I have a wall with a large (4 klf) and I am concerned that needling may not be sufficient to shore a load of that magnitude. Any thoughts would be greatly appreciated.

 

[dik]

Needling is common for providing temporary support for CMU walls. Your 4klf loading appears to be high. Have you considered arching for the load? If the load is of that magnitude, rather than needling, you may have to cut in a steel channel on one side to provide support and then install another one on the other side. Alternatively, you may have to provide temporary support for the load and then provide needling.

Dik

 

[kmead]

dik,
Thanks for the quick reply. I have considered arching but there isn't enough CMU above the opening to allow for arching action. As for shoring the load, it is actually very complicated because of existing ductwork and other obstructions that limit that option.
I do like the idea of cutting in a steel channel on one side like you suggested. I will look it, otherwise I may not have a choice but to shore the load regardless of the inconvenience.
Thanks again for the helpful information.

 

[jike]

If there is load coming unto the wall from say a floor or roof, you might consider shoring those elements separately from the wall.

 

[rnorth]

can someone give an explanation of needling?

 

[dik]

Needling is the process of putting holes through a masonry wall and providing a support of it at the hole location.

The holes can be large 12"x16" and the 'needle beams' can be W12x26 for example. Alternatively, the holes can be small, ie. 3/4" diameter and the 'needles' can be threaded rods. Often dimensioned lumber to PSL material is used on either side of the wall with 3/4" dia threaded rod at 2' centres (for example only) are through bolted and clamped. The ends of the PSL is supported by posts. The masonry beneath the needle beam is then removed and a new steel/concrete/masonry lintel is put in place and the needle beam is removed.

Dik