Another 100 year old brick building. 2

[idecharlotte]

I too have recently become involved with determining a repair for a 100 year old, 3 story brick building. Here's the situation: An old theater adjacent to the building in question was demolished. They decided to rip down the wall of the theater that was against the wall of this building. In doing so, they failed to cut some of the wall anchors and as result the wall was pulled out of plumb about 2". The corner is cracked and separated. The floors are wood joists pocketed into the masonry. Now this 100 year old wall is exposed and appears well deteriorated. It's a 12" masonry wall, about 12 feet between floors. They want to make it "safe". What is considered "safe" from a repair perspective? Does it need to meet the current Code? There was no earthquake Code when it was built and it is also now exposed to wind and erosion. I was planning on restoring the eroded brick and anchoring the joists to the wall and the wall corners back together. Doing that alone will not come close to meeting the current Code requirements for earthquake. Oh and by the way, It's occupied by tenants. Any ideas would be greatly appreciated.

http://www.idecharlotte.com

 

[civilperson]

Steel braces installed after/during repair of masonry. Must achieve code compliance.

 

[dik]

Depends on the jurisdiction about how much you can 'grandfather' stuff. Depending on the construction and restraint, 2" may not be excessive.

Another concern is that often for old masonry, if they were constructing 'tight' to an existing building, they may have used a lesser quality brick realising that the envelope was not exposed to the elements.

Dik

 

[hokie66]

In addition to structural concerns about the wall which is now not plumb, I would investigate any legal issues.

Who is responsible for rectifying the damage? Was the old theatre on a separate property? Does the wall in question now encroach?

 

[idecharlotte]

I work for the landlord who owns the building. The city owned the theater that was torn down and is claiming responsibility for the accident as well as paying for all repairs. There is no legal issue and likely will not be...unless of course the wall falls down. Also, because the city is also the inspection department, they ultimately can override the building Code, and in this case it sounds like they are willing to, since they are paying for the repairs. So my plan was to design to meet the 100 year wind speed and earthquake activity in the region, which may be less than the loads from ASCE 7.
My biggest concern is how to properly repair crumbling brick. If anyone has any thought or references that would be helpful. Thanks for the replies.

http://www.idecharlotte.com

 

[Ron]

Are you trying to maintain a historical perspective for the building? If so, that will dictate much of your repair scheme. If not, then you can do what you want.

I have done evaluations of the brick for old structures and find that old brick often has significant issues. You might want to get a petrographic evaluation of the brick. Secondly, you can replace the brick with replicate brick, building in additional structural capacity. When I have cross-sectioned and examined old brick microscopically, I've found that it often has a strong shell layer and a weak interior, most due to poor firing techniques of old. That leads to crumbly brick and high water intrusion.

 

[beton1]

If the joists are pulling out of their pockets, you likely require some sort of system to pull the wall back in, depending on joist bearing (loss of) before anchoring them. It can be done, but the external anchorage may have to remain, and this could be a aesthetic issue. It is also a nerve-wracking process. You could try to use this system to build in some upgrade or stability. If the wall has moved, there is likely mortar damage, and any cracks can allow water in which can potentially cause other problems.

 

[dik]

There's a posting of Historic Brickwork on SlideRuleEra's site you might want to read.

Dik

 

[csd72]

If the 2" is at floor level then provide sufficient ties in the floor to take out the horizontal component.

2" is small compared to the out of plumb on some of the buildings and arches over here in the UK. Tying back is standard procedure over here and is the first thing they look at with an existing building.

I saw a good article on this and will see if I can try and find it for you.

 

[civilperson]

The code is considered good JUDGEMENT. To ignore the code because the client is a city seems to be poor judgement with unlimited inherent liability for everyone concerned. Grandfathered existing buildings are nor failing and in distress or different from original constructed condition.

 

[idecharlotte]

Attached is a picture of the wall. The right side of the photo being the front end is where it is separating. The whitewashed wall is the remaining portion of masonry wall from the old theater that they decided to stop removing once they realized they were damaging the other wall. The owner wants to build a double wythe masonry wall off of the old theater wall and attach it to his wall as protection and reinforcement. The city is willing to give the owner the property of where the old theater wall was to do so. It's an ugly mess.
I did reexamine the mortar. It's pretty solid... not easily chiseled which leads me to believe it is portland cement.
I got some clarification with regards to repair. They want it to structurally be as strong as it was in it's condition before the "accident". That makes it easier to determine the repair. I plan on tying the wall corners together with steel bracket ties in both directions. I don't think I'm going to try and pull the walls back together, just replace masonry and repoint the mortar. Do you think there are any negative implications with tying new brick to old? There are no expansion joints in the old brick.
Thanks again for the replies.

www.idecharlotte.com

 

[msquared48]

"...the city is also the inspection department, they ultimately can override the building Code, and in this case it sounds like they are willing to, since they are paying for the repairs."

This is a dangerous condition for your client and the tenants. Do not compromise public safety to save the city money. This would be bad engineering.

Mike McCann
MMC Engineering

 

[BAretired]

It might be worth looking at reinforced, pneumatically placed concrete. This would strengthen the wall and protect it against the weather.

BA

 

[SLTA]

I completely agree with BA - reinforced shotcrete will help. You might also look up a preservation engineer in your area for experienced opinions about this exact issue - it must have happened before in big cities.