Buttress Vs Car 1

[BubbaJ]

Currently have a repair project where a late 19th century stone buttress took on a car and lost.

I was amazed they still had the original drawings.

There is a plaster crack in the corner on the interior, otherwise no other damage observed on the first floor or in the basement. The perpendicular buttress has been rotated with about a 1" gap on the backside where it meets the building wall.

As you can see, the interior of the stone wall is a jumble of partially mortared rubble and the limestone was drystacked. The two buttresses at the corner will need to be rebuilt.

The question I have is do we rebuild with rubble, keeping in the style of the original construction and in doing that fully grout the cavity so we can establish interlock with some tie stones from the limestone? When fully grouting the cavity we would need to dam up the voids behind to prevent it from filling the whole wall and take into consideration some additional deadload on the foundation. There isn't really much for tie stones currently, it appears a large majority of the stone was just butted up to the buttress from the wall.

Or, do we have the contractor drystack the limestone exterior utilizing tie stones, then grout the cavity behind, not worrying about trying to fill it with rubble? (Still blocking off the existing voids in the wall to prevent filling the whole wall.)

Thoughts? I'm not finding much for resources for repairs of this type. TIA

 

[LittleWheels]

The Historic England website might be a good place to start looking.

https://historicengland.org.uk/advi...gs/maintenance-and-repair-of-older-buildings/

has links to guides for maintenance and repair of structures made with various materials.

Are there any preservation or conservation restrictions on the building that would limit what work could be done or how it was carried out? If so, that will quickly narrow down your options.

 

[bridgebuster]

Out of curiosity, where is this and what happened to the car?

 

[BubbaJ]

The Historic England website might be a good place to start looking.

https://historicengland.org.uk/advice/technical-ad...

has links to guides for maintenance and repair of structures made with various materials.

Are there any preservation or conservation restrictions on the building that would limit what work could be done or how it was carried out? If so, that will quickly narrow down your options.

I did find that same resource. They have much older buildings that the States, so it makes sense they have the best info.

It is on the Resister of Historic Places, so there will be restrictions. Thank you for reminding me to check that.

 

[BubbaJ]

Out of curiosity, where is this and what happened to the car?

Iowa, and the SUV, alleged to have been speeding, burst into flames. The driver was seriously injured.

 

[bridgebuster]

One thing to look into since this is on the historic register, whether or not you need to reuse the existing mortar. A few years ago, I designed a highway off ramp widening. The existing stone parapet on the retaining wall was considered historic. We couldn't put a stone parapet back because it didn't meet current crash requirements, but we had to had to replicate it (reinforced concrete & reuse the old stone) However, the DOT's landscape architect said under these circumstances we didn't need to reuse the existing mortar. Something to consider.

 

[phamENG]

bridgebuster - reuse, or match? Not sure how you'd go about reusing mortar....

Matching the mortar to the masonry is important for historic structures whether they have historic restrictions or not. Failure to do so can cause lots of problems, especially in areas with high moisture and low temperatures.

 

[BubbaJ]

One thing to look into since this is on the historic register, whether or not you need to reuse the existing mortar.

Incorrect mortar and repointing techniques were noted across the existing structure. Someone used cement based mortars and ribbon type repointing which is pronounced from the face of the stonework. That material is easily broken off by hand.

 

[bridgebuster]

phamENG - you grind it into powder, mix , etc. From what I was told it's more trouble than it's worth.

 

[phamENG]

Interesting. I guess you'd still have to introduce some additional binder since the ground up stuff is already hydrated. I've never heard of anyone doing that, though, and we have some strict historical guidelines around here. (The oldest surviving brick dwelling in North America is 45 minutes from my house.)