Roof removal analysis

[hitch22]

Hello folks,

I interested in removing the roof of a building as this is the only way to put new equipment. Because of this I need to analyze the problem and see whether the building is stable while the roof is removed. In parts of the building I must take out roofing panels, and perhaps in another part of the building, one or two braces. Could someone please guide me as to what things you would consider.

Of course I must consider wind loads, but I am not sure how to use the National Building Code of Canada for a structure with no roof.

Any help would be greatly appreciated. Thank you very much.

 

[MiketheEngineer]

You might consider getting local professional help.. Depending on a lot of things - this could be rather straightforward or quite difficult.

From 1,000 miles (1609 km) away - can't be much help.

Sketches, dimensions, pic always help...

 

[dhengr]

Could you open up a few areas of exterior walls (or only one opening) and skid the loads into place? You aren’t removing the whole roof to do this are you? You are only opening some areas, right? You have to look at both options to see which is most practical and cost effective. But, I agree with Mike that sketches, plans, bldg. sections, equipment sizes and weights, etc. would be helpful if you want real help. And, if you have any doubts, local Structural Engineering help might be best.

 

[Ron]

The roof would likely be only a structural help for lateral diaphragm for wind loads or for seismic. Considering that this is a short term condition and you can likely predict wind issues within a reasonable timeframe, I wouldn't worry about that. For seismic, you have no prediction and must consider bracing if the roof serves as a lateral diaphragm.

 

[hitch22]

Thanks for your input. I have attached a rough sketch of the roof. For the section in green, only the panels will be removed. The part in the purple was made to be removed and so the structural members will come off as well. The part in the orange will require removing at least one of the braces.

In this part of the world seismic risk is low.

 

[hokie66]

I am assuming this is a steel framed, braced building, with purlins and metal roofing. Is that correct?

If so, I think you are safe to take apart the parts of the roof necessary to lift in the equipment, then put it back together. Limit the time when the roof is open, do it in good weather conditions, and you should be fine.

 

[hitch22]

Yes this is steel framed, braced building, with purlins and metal roofing.