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Mass realty check...

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Hey gang:

 

I am currently working on the conversion of an existing four story heavy timber “loft” building

In the Boston suburbs from light manufacturing to residential condominiums…

 

The way I read the Mass Building Code, due to the renovation work and change of

Use, the existing building must have a seismic/lateral analysis performed on it.

 

The problem is, there is no existing lateral load resisting system.

 

The building is composed of unreinforced masonry (multi-wythe brick) bearing walls at the

Perimeter with steel pipe columns supporting heavy timber purlins and wood decking.

 

The Mass Code, like most others, does not permit the use of unreinforced masonry (except that which

Is used as infill for a concrete frame) as a lateral load resisting system.

 

Using this logic then, the building must be reinforced to meet the provisions of the Code.

Btw, my solution is to install interior steel braced frames which engage a new concrete topping to increase

The diaphragm capacity. (I can go into this later…if anyone cares…)

I’ve taken into account all the Code reduction factors for existing construction to reduce the magnitude of

The lateral force (in this case, they let you reduce the force by 60%!); the professional ethics of that

Was can debate another time, I guess…

 

 

The owner, as you might imagine, is having a fit about all the extra steel and foundation work he has to do

Because of this…and being “the out of town guy” doesn’t help.

 

Am I crazy? (I am just referring to this issue, not my various other sm*rt *ss list comments over the years)

 

Help!

 

David L. Fisher SE PE

Senior Principal

Fisher+Partners

 

372 West Ontario

Chicago 60610

 

312.573.1701

312.573.1726 fax

 

312.622.0409 mobile

 

www.fpse.com