Overcoming barriers: A Vermont slate roof in Peru

February 28, 2017

The Search Begins

When RAMSA, the world-renowned architectural firm in Midtown Manhattan, specified a new Vermont slate roof and custom-fabricated, sheet metal, barrel dormers on the Pezet Complex in Lima, Peru, many on the project shuddered.  Slate roof?  Slate roof?  There aren’t any slate roofers in Lima or even in all of Peru.  How could this be accomplished?

The search for a solution began.  It was a tall order:  How can slate experts be brought in to do such a project when weekly wages were typically less than one day’s wages in the US?  What company had the wherewithal to provide liability and workers compensation in a foreign country?  If they brought in a trainer, what trainer could train a crew so quickly?

After looking long and hard, The Durable Slate Company, was approached with various ideas on how the project could be completed.  The solution was formed: 2 weeks of hardcore training with John Chan, Vice President of The Durable Slate Company and President of the National Slate Association, and Shane Day, Director of Special Projects for The Durable Slate Company.

Prior to arrival, John did a full-scale take off of the plans and site.  All the plans had to be converted from metric to standard measurements as well as from Spanish to English.

Four containers of Semi-weathering Gray Green slate were ordered from the New England Slate Company.  In addition, all the sheet metal, soldering equipment, roof scaling equipment, copper nails, rivets, hand tools, etc. were all part of the shipment from the US to Lima, Peru.  None of this was available in Peru.

Paradise in Peru?

January in Ohio was snowy and dreary; Lima on the other hand was fabulous.  The temperatures were around 75 degrees with a slight breeze off the Pacific Ocean.  How could things be better, so we thought!!

Trouble in Paradise!  Upon arriving at the Lima jobsite, the Durable Slate team noticed several things:  The wood wasn’t installed correctly to install the roof.  John and Shane quickly told the carpenters that more rafters were spaced too far apart (up to 30”), and the hips needed to be straight.  The initial inspection showed the hips to be 3”-4” out of line.

Unfortunately, the Peruvian carpenters didn’t speak English and the translator had not arrived yet. Immediately upon the translator’s arrival, the wood decking was quickly stripped off, and Shane worked with the carpenters on how to install it correctly.

Meanwhile, John assessed the inventory; thankfully it was all there.  Next, he got a crew of Peruvians to shuffle the slate.  Next was fabricating the sheet metal drip edge, step flashings, and valleys, but another problem – NO SHEET METAL BRAKE!  Somehow, there was a misunderstanding of what a brake was.  Now two days into the project and not one piece of slate or sheet metal had made it on the roof.  Things weren’t looking so good.  Finally, a sheet metal brake was located.  Arrangements were made to bring a heavy-duty shop brake to the jobsite.

Day 3 – The slate was about 25% shuffled to ensure an even color variation.  The brake was on site, and the Peruvian crew was ready.  Shane took two of the Peruvian guys and taught them how to mark, cut, and bend metal, so that we would have all of our needed drip edge, step flashings, aprons and valleys.  John took the other guys to the roof.  The roof was measured out and chalked.  The slates were craned up and set up.

The drip edge and cant strip (a wooden strip used to start a slate roof at the eave) was installed.  The first slates start going on the roof.  Each roofer is shown exactly how to nail – no over-nailing and no under-nailing.   At the end of the third day, there was only about 20 pieces of slate laid.  However, they all knew how to nail a slate and how to cut a slate.  Shane’s guys all knew how to mark, cut, and brake sheet metal precisely.

Day 4 – Shane’s guys learned how to install an apron flashing and how to step flash a wall.  Meanwhile, John showed his guys how to lay out a roof when it’s not straight – angling the tape measure to give an illusion of perfect lines even when the carpentry was far from perfect.

Overtime, the Peruvian team learned the nuances of slate roofing: how, why and where to punch new holes, how to set roof jacks and boards, how and why one needs to shoulder slate (cut one of the top corners of a slate off when it’s warped, allowing the slate to lay flat).

Day 5 – The slate guys were learning how to pick up speed on the large open face, and they were shown how to terminate the slate at a pitch transition.  Meanwhile, Shane was showing one of the guys how to install drip edge and metal around a curved dormer.  Unfortunately, they insisted on a certain color of gray metal.  They decided on using Paint-Grip Galvanized steel in lieu of copper.  Therefore, there were no ornate folds, but locks/rivets and solder.  It was shocking how quickly the new roofers picked up these new skills.  The first dormer was all cut in and riveted.

Day 6 – Saturday – The short three-hour day didn’t allow for much work except a brief review on the progress and practices learned so far.

Day 7 – Shane showed his guys how to solder and VOILA!  The guys could fabricate and install barrel dormers after just a week of working with them.  In the meantime, John showed the guys to install the metal flashing on the hips and how to install hip slates, keeping the lines straight.

Day 8 – There’s a time crunch coming, because ten days is coming up FAST!!  Shane continues working with the guys on barrel dormers, while simultaneously installing the transition metal on the pitch change of the mansard.  In the meantime, John is diligently showing the guys how to lay out the top mansard roof with a 6” head lap.  They were advised to put standing seam on the top of the mansard, as the pitch was only 2.5/12.   However, the architects insisted on slate.  Unbeknownst to us, the architects had also specified a modified bitumen roof on the concrete deck prior to the wood battens and wood decking was installed.  So we went ahead with the slate roof with the 6” head lap.

Day 9 – The roof is going well, except there are still a number of things that haven’t been taught yet.  Lists were compiled: how to tear down the roof jacks and boards, how to do repairs, how to install valleys and chimney flashings.  Those haven’t even been built yet!  Shane and John began to break down the completed faces, showing the guys how to take the jacks and boards out of the roof, and how to use a slate ripper to remove broken slates and how to repair the broken slates.  The guys were shown the YouTube video from The Durable Slate channel as well as how to do it in the field.   Wooden boxes were installed on the roof so that we were ready for our last day for chimney flashings and valleys.

Day 10 – We taught the guys how to flash a chimney and install a valley on the roof, and those parts would be left in place so that they crew could refer to them in the future.   We ended the day with lots of group pictures and good byes!!!  One more ceviche dinner and then we had to clean up for a Midnight red-eye flight back.  We overcame all the barriers thrown at us and came out with a fantastic product and the FIRST Vermont Slate roof in Peru!