We had emergency repairs done to the east and west parapet back in 2009. Back then I had the hunch that additional work may be needed once we began redoing the roof. That hunch became a prophecy.
Don’t get me wrong. The parapet repairs from 2009 were perfectly fine. The issue that I faced had to do with roof insulation.
We insulated the roof between the rafters. And I learned (the hard way) that we needed to continue with the roof insulation above the roof deck. The insulation above keeps the roof deck on the warm side so stays drier during the winter months.
Adding layers of insulation onto the roof deck shortens the height of our current parapet. To maintain the code required height, I needed to raise the parapet. I called our mason back and purchased a few pallets of additional salvaged common brick.
I mentioned a couple of posts back that working with common brick requires certain steps and a certain type of mortar to produce a lasting masonry system. And I have described the process and materials in a previous post (Mending more masonry + Bricks and mortar). I recommend that you look up that post if you plan a project that would use Chicago common brick.
One key aspect is to make sure the common brick is properly soaked in water prior to installation. This prevents the brick from pulling water out of the mortar. And that in turn provides the desired bond between the common brick and mortar.
It is also a good idea to keep wetting the brick during and sometime after the installation for the same reason. So I kept busy spraying it down. This can be a full time job during a sunny and hot day. The common brick dries out rather quickly. Cooler and overcast days are easier.
The cornice was repaired and re-attached to the masonry. It was time to call the mason back to finish the brick work on the front parapet.
The parapet repair behind the cornice was all done using common brick. From the cornice tie-in upwards, we switched to Roman face brick. The same brick that was used below on the front façade. Lucky for us, there is one company left in the Midwest (the Belden Brick Company), that still manufactures Roman face brick.
But we didn’t just use Roman face brick. To keep with the architecture of the facade below, we integrated graystone into the front parapet. This is the graystone that I salvaged a few years back from buildings that were torn down nearby.
The front parapet has a depth of three wythes. We rebuilt the wythe facing the street with graystone and Roman brick. The other two wythes behind it were invisible. Here we used regular common bricks again.
To render the common brick stable, we used header courses to tie the wythes together. To connect the street-facing wythe – the graystone and Roman brick – I used ties to connect the graystone pieces to the common brick behind.
Getting the cornice and front parapet repair out of the way was a major milestone. I could now focus on raising the parapets along the east and west sides in preparation for the re-roofing.
I covered in the previous post how we removed the old and crumbling parapet until we hit solid masonry. This post will cover the first stage of the parapet rebuilding.
I had to break-up the process into stages, because along the way, I had to repair the cornice that was attached to the masonry. I will cover that part in the next post.
We started the rebuilding from the solid masonry we had exposed, up to the level where the original cornice roof tied into the masonry. The new cornice roof, which we were about to install, will tie in at the same masonry course.
The parapet had a depth of three wythes. The cornice would only attach to the first wythe, which meant we could continue to raise the back two wythes.
Like most of the building, the core of the parapet used Chicago common brick. Working with common brick is a different process than working with modern brick products. It requires certain steps and a certain type of mortar to produce a lasting masonry system.
I have described the process and materials in a previous post (Mending more masonry + Bricks and mortar), and recommend that you look up that post if you plan a project that would use Chicago common brick.
Did I mention that the front parapet was badly crumbling? If you wonder why, the answer is easy: bulk water infiltration into the masonry.
The cornice roof (a copper sheet) was supposed to shed water away from the building. Not only did the cornice roof come apart at the seams, it had bent inwards, allowing water to pond right behind the edge. To “solve” that problem, a previous owner had punched small drain holes into the copper sheet, allowing ponding water to enter the cornice interior and the masonry behind.
Some of that masonry had deteriorated so badly that someone put a layer of cement parging across it to prevent it from falling off. That, however, further aggravated the problem, because the cement parging trapped moisture and prevented the masonry from drying out.
We went around and peeled back the roofing membrane which was lapped across the parapet. Underneath that, we found rows of mostly loose brick, if we were lucky. Behind the cement parging, we found brick crumbles.
There was hardly anything to salvage. We scooped up all the loose material and slowly worked our way down until we hit solid masonry. That meant in many cases going down to the bottom of the cornice.
From this point on, we could begin to rebuild the parapet in stages, and along the way, repair the cornice.
As usual, many thanks to our skilled friends Augusta and Rubani who helped us in this adventure.
Our house came with a beautiful cornice that was attached to and supported by the parapet behind it. It was constructed out of copper, but the bottom section had been painted, unfortunately.
It has terrified me for years. This was because upon closer inspection, the top of the cornice was in dire need of repair and we had water infiltration issues, which led the supporting parapet to crumble. And no matter who I asked, I never got a straight answer on how it actually was constructed, supported or attached to the building. It remained shrouded in mystery, leaving me to procrastinate.
With the looming solar array installation, there was no avoiding this any longer. I opened up the top copper sheet to get a visual on the inside and the attachment mechanism – or lack thereof. And the more I started digging the more terrifying it got.
The “support mechanism” was rotting pine boards, which were rotting either in the masonry or the opposite end. And the supporting masonry had deteriorated into loosely stacked bricks.
The crumbling masonry had to be removed and rebuilt. The bottom of the cornice was salvageable, but the top sheet had to be entirely replaced to prevent any further water infiltration into the masonry behind. Mind you, the job of the cornice is to shed water away from the building façade. Along with all this we needed a new support mechanism.
To save and reuse the bottom section of the cornice, I had to brace it before I could remove and repair any of the masonry or top copper sheet. The last thing I wanted was for it to fall off the building.
I managed to score a stack of reclaimed two by fours at The Rebuilding Exchange, which I used to rig up a solid bracing system.