If there are only brick walls, then it is possible that you have 3 wythes of brick.  Humidity from within the home used to wick through the mortar joints.

With changes in life styles, homes have more humidity and are generally more air tight.  You have to be careful about the building envelope too.

That said, your interior partitions could be providing a substantial stiffness to the home and some skill and care in selecting what can and cannot be removed is required.  The original walls could be wood lath and plaster which if in good condition is 'very' stiff and provides a substantial lateral stiffness.

Just some caution when dealing with historic masonry.

Dik

You may want to read a paper that the member who made the previous post, dik, authored and has kindly allowed to be made available on my website. See "Historic Brickwork (2008)" near the top of this page:
http://www.slideruleera.net/contributions.html

www.SlideRuleEra.net
www.VacuumTubeEra.net

Thank you, DIK and SLIDERULEERA.

The building has been used as a warehouse and there are not much partition walls. The perimeter wall is the prime gavity system and lateral system as well.

The 3-story height perimeter walls are braced by the wood floor and the wood floors (as a diaphram) are redistributing the later forces to the adjacent transverse direction brick walls which is kind of big partition walls (about more than 50' spacing). Well.. the building has more likely empty inside.

If this is the typical historic brick building strutural system, do you have any suggestion before I try to remove the second floor level wood deck frames? Any lateral stability issue? I cannot imagin the building collapsed after I remove some part of the existing system.

Thanks for any opinion.

We did this at a Stone load bearing wall before.  Whenever we had to remove part of the diaphram (a floor), we put something back.  In this case we put beams turned on their side to take the wind load and anchored them to the stone.  Anchorage can be a concern, but it has to be as good as the pocketed beams in the stone.  The beams we would run all around the building, or until it was appropriate to put a column and a brace to the other side of the building.

Andy

You will need to brace the walls throughout the construction period to provide lateral stability. However, you maybe able to avoid the bracing if you can find ways to erect the new floor before get rid of the old. You will also need to make sure the walls below the new floor are adequate for the 5' increase in vertical span length.

Check wall stresses under wind load and slenderness for axial load with the temporary conditions of the floor removed. If it works then okay if not then you need to provide propping (shoring).

Thanks all,

I have much better feeling on this project now. Still I have to think about the transvers direction shear resistance system using brick partitions or something else, otherwise this building will never meet new IBC seismic requirement to complete the massive renovation. It is a bit amazing this building is still standing without such lateral stiffness and without any trouble. It is lucky this site is not in severe seismic zone.

Thanks for your great idea and concern. feel free to add any comments. Thanks

If there is 5' difference between the old and the new then there is no reason why they could not install the new floor before demolishing the old.