The Cloister Style Pergola, Part Two

You may not have read in November of last year a post about a landscape renovation that we have had underway since June of 2018. A part of this project in process involves the design and fabrication of a large scale cloister style pergola. The story behind the design and fabrication? Click here for the details.   the design and fabrication of a steel cloister The 2018 story concluded with that moment when 18 tons of steel sections and parts finally made their way to the site for installation. Of note was the fact that wet weather necessitated building a road back to the installation site. A structure of this size had to be assembled on site, so Buck engineered it to be put together and set up one section at a time. Just before Thanksgiving, a large boom crane moved in for the duration, as each section of the structure would be far too heavy to maneuver by hand.

It was slow going. The weather was bitterly cold and muddy. The finished size of this structure is 47 feet long by 36′ wide. I have no idea how many pieces there were in total, but there were enough to call the installation of this pergola a puzzle of enormous size. To make every section line up perfectly so it could be bolted to the previous section was daunting. The process made my eyes water.

Eventually the structure took shape. Seeing it go up was an experience like no other I have ever had as a designer. The model I built my client was the size of a piece of copy paper- 8.5″ by 11″. Of course the model did not at all describe the actual structure that was to enclose 1700 square feet. The model was a not so accurate expression of a structure as it was an attempt to express an idea of the landscape shot through with romance. What?? Romance is my middle name. Ha. As much as I admire classic French landscapes for their edited expression, and coolly compelling geometry, Italian gardens and landscapes have that element of romance that I find irresistible. As for this steel cloister, suffice it to say the design is as more about my client and her love of the garden than anything else. Though I had spent hours going over every proportion and detail, at some point I had to commit to a design. And a presentation of that design to my client. In May of last year, she decided to go ahead and build.

Cloister? In its simplest form, a cloister is a covered walkway. This structure has a six foot wide walkway all the way around the perimeter. That walkway is covered by roof panels constructed in an open and elongated diamond pattern. The cover will provide some shade, but will permit light and rain to come through. That pattern is repeated on the fascia panels at the top. There are 32 round columns, each of which is bolted to a concrete foundation that goes 42″ deep into the ground. Between each pair of columns is a pair of curved steel brackets. This curved detail compliments the roundness of the columns, and the solid steel spheres that ornament the structure.

Buck’s first drawing of the cloister showed square columns. The look on his face when I told him that I wanted round columns was an unmistakable sign that I was asking for the moon.  After he explained that engineering flat surfaces to perfectly line up and be attached to a curved surface would be just about impossible, I paused. The roof and fascia panels would be built from round rod, and each panel would feature steel spheres. The round columns would be essential in giving a structure of this size a graceful appearance. The architecture of this stately old home was not asking for an industrial look. Please? He relented.

Buck did a superb job of engineering, and his group did an equally fine job of fabricating. My client took this photograph and the following one after a snow storm this past winter. I was delighted to see how the snow outlined and described every detail of the structure. It will be a feature of the landscape every season of the year. As planned, the cover over the walkway was permeable to both light and water. In the immediate foreground of this picture is the roof of a very simple version of the cloister over the dining and grilling terrace that is directly adjacent to the house.

The snow made it easier to see the long diamonds and dots pattern on the roof, fascia panels, and the main entrances into the space.

Now that the long winter is over, we are back on the project. I have every confidence that come late May, this landscape will be ready for her to enjoy. We have little to do in the interior of the pergola. Bringing up the soil level to grade, planting the roses, installing the edger strip and grass is about it. The irrigation in this area is underway, and the tile for the fountain pool is due in May first.

This was the first time I had seen the completed structure since the work began. I was thrilled with how it looked. And incredibly appreciative to have a client who made it possible. Their are limestone stepping stones yet to come. I had the roses custom grown several years ago. Dan and David have been growing them on, so we would have plants of some size from the beginning. The furniture and pots for this area have been in storage at our landscape building since last September. Though I will probably post about this project again when the landscape is complete, this is a very special moment for my entire group. The best part?  Our client is pleased.


In the homestretch now.

Part Three: The Pergola

If you  have been reading this series of posts, you will recall that my landscape design called for a rectangular cloister style pergola to be built off my client’s sun porch and garage. That shape was dictated by an L shaped space established by the sun porch, and the long back side of the garage.  The center of that cloister would be a fountain pool. My drawing, pictured in the previous post, was schematic, meaning that drawing was a generic structure, just holding a place on the page.  Once she indicated an interest in a pergola surrounding the fountain, I went to work to actually design that structure.

 

 

So what is a cloister?  A cloister is a covered walkway, frequently surrounded by a building or buildings on all four sides. Historically, it was an architectural feature common in monasteries and courtyard spaces in universities. The design for this pergola is predicated on a 6 foot wide covered walkway which would provide overhead structure to the fountain pool. The photo above shows Buck’s CAD drawing of the long side, which is almost 47 feet long. The design revolves around a series of elongated diamonds of different sizes, and steel spheres of 3 sizes. Buck added some figures to his drawing, so I could see what the relationship would be between person and structure. A good part of the reason it is 11 feet tall is its placement. Standing at the bottom of five steps from the sun porch grade, it was important that the roof did not appear too low from that vantage point. That height will also give it some presence from the upstairs windows, and the balcony which is on top of the sun porch roof.

This drawing of the roof panels makes clear the idea of a covered rectangular walkway. And that the interior space would be open to the sky. It was almost a year ago that we ordered the John Davis roses that would be planted on the pergola columns. I still have hopes of putting them in the ground yet this year, but if not, we can winter them over in our landscape building.

The drawings are useful to a designer, but maybe not so much to a client. Buck figured out how to scale the three drawings the same, and I built this model from sheets of copy paper. Buck drew the schematic for the pool on the roof plan. All of the white spaces on the paper will be open spaces.


This model came months after the presentation of the original plan. Once my client approved it, there would be much more work to come. Not only were there engineering issues to sort out, all of the dimensions would have to be coordinated with Mike Newman, as his steps and walls were an integral part of the installation. The following drawings were passed back and forth between Buck and Mike, so all the the locations and dimensions could be mutually agreed upon before anything was built.

This plan view of he steps, walls, and pergola show the relationships between the various elements. The walls would have 2  12′ wide openings that would provide access to the back and side yards. Upon reaching the bottom of the stairs, there would be 5 feet of open space before reaching the pergola.

These drawings do the best job of illustrating the fact that there are pairs of columns that would hold up the roof. There are 32 in all. And the columns are round.  I designed as much of this pergola to feature round shapes, as opposed to square or rectangular. The round shapes seemed less industrial, and more fitting to the period of the house. Buck said this decision made the engineering much more difficult, but I think it will prove to be well worth the trouble.

view from above

view from the far end

the view of both exits

Pictured above is a group of the roof panels, after the galvanizing process. The round rods are captured in a square steel channel. The solid steel spheres, welded at the juncture of every other diamond, will face down. There are 2000 of them, in all.

These fascia panels feature a larger gauge steel rod, and 2″ diameter solid steel spheres. These are finished panels in their raw steel state.

The pallet in the foreground is stacked with the pergola entrance panels. These have the largest diamonds, and 3″ diameter steel balls. In the background, pallets full of columns.

Branch limited the weight of every pallet so it would be easy to offload them at the site.

Prior to loading up the pallets, Buck had his guys pick random pieces from each stack of parts, and had them put together one 12′ by 6′ section. He wanted to be sure all of the parts would go together easily. Putting a pergola together in the field is a much different operation than putting it together in a warm dry shop, with a bridge crane overhead. The install will be lengthy, as it is a big structure. Maintaining the precision with which each piece was fabricated was a challenge. That precision is what will make the install go smoothly.

This view from the mezzanine at Branch shows a roof panel set in place.

Jackie arranged for a dedicated flatbed truck to transport the pieces to the job. Even so, there were 6 pallets left over that my landscape crews loaded in their trucks. None of the pallets could be stacked.

We had our loader on site, so we could offload once the truck arrived.

There was one part to the story we did not anticipate.  3.5 inches of rain fell in the area where the boom truck would be located, and those pallets would be staged.  We had not gotten to a finished grade in this side yard. The ground was very low here. Our original delivery and installation date came and went. I was not pleased with the prospect of having to waiting until the ground froze. I put in a call to my large tree contractor, and asked if there was anything he could do.

Ralph brought in 80 yards of sand, and 100 sheets of 3/4 inch thick plywood, with the intent of building up the grade such that we could access the site.

He built a road in that would be able to handle the weight of the pergola pieces, and trucks. Fortunately, this side yard is still so low, that all of that sand will eventually become part of the finished grade.  He is estimating he will need another 200 yards of soil to bring this space up to grade.

The boom truck is an incredibly heavy piece of equipment, featuring a large arm that will pick up each piece in the proper building order. That truck has huge steel arms that come out, and rest on the ground, to stabilize the truck.  Plywood and sand would not be enough to keep that truck stationary.  The construction mats you see in the above picture weigh 1000 pounds each. Ralph assured me that they would stabilize the ground for any truck we needed to get back there.

finishing up the road in

Sheets of plywood were all we needed to stash the various pallets.  The boom truck operator will be able to pick up any part he wants, when he needs it. It took 3 days to get the site ready. Templeton Building Company will do the actual installation. Buck will be there the first day, to advise.

Everything is ready. The boom truck is scheduled to arrive this afternoon. I hear the scaffolding is going up now. Each column will be bolted to the footings that Mike poured some time ago. The structure will be bolted together, one piece at a time. It could take a week, from start to finish. For now, I am just very happy to know we are in the home stretch.