Worn limestone exterior

[Mike Lamb]

I am wondering what advice I can give on the exterior limestone of this 17 year old building which is noticeably wearing away (spalling?). I’m not sure of the cause. Traffic pollution? The wearing away is not just confined to the lower areas.

[Mike Lamb]

The more I look at the other photos, the same thing is happening at the limestone facing even up at the roof line. Would sealing the stone with an appropriate sealant help slow the problem?

Edited August 5 by Mike Lamb
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[Bill Kibbel]

Are we sure it's not cast stone?  It's hard to tell from the pictures.  I think I'm just not seeing what I expected for limestone.

[Mike Lamb]

It could be cast stone. I don't know how to tell the difference. Would repair or maintenance be different? And what should be done about this. Thanks, Bill.

[Mike Lamb]

After some research you are probably right (as always). Cast stone.

[Bill Kibbel]

If it's cast stone, there are many products available for consolidating, repair and protection that certainly can't be used with limestone.

One of the Preservation Briefs deals exclusively with cast stone.  There's some info about spalling/erosion/deterioration and repair methods that might be useful here.

[Bill Kibbel]

It's Preservation Brief 42.  I uploaded a pdf - click on the Library menu tab.

[Mike Lamb]

Thanks, Bill.