Avon Grove High School Roof Assessment Avon Grove High School Photo Report for Roof Evaluation and Assessment Bill Pancoast and Chris Gallagher The Garland Company, Inc.
Satellite Imagery
Roof Plan
Roof Plan 1997 Construction
History of AGHS Low Sloped Roofing The low sloped roofs are Tremco BurMastic built up roofs consisting of three plies of fiberglass and polyester felts in solvent based asphalt adhesive over 2” polyisocyanurate insulation and a ½” recovery board (Aged R value of 10) The performance of this BUR system has been poor with a history of longitudinal splits through the felts that are difficult to anticipate but when they occur they typically are wide open. This is compounded by the presence of massive areas of ponding water that will drain directly into the building and over time affect the structural integrity of the gypsum roof deck below. The Federal Government settled a case with Tremco resulting in a $61,000,000 settlement for failing to give the same discounts given non- federal customers, Charges are that their 200, 400 and 500 roof systems contained defective products and that the repairs being made to correct to situation were inadequate but they continued to sell the systems anyway The AGHS roofs vary in age back close to 20 years as they were done as part of a multi year program. Most recently, they started to resaturate the roofs with additional solvent based asphalt adhesive that will do nothing to prevent splitting of the felts. That program was halted prior to completion saving the district $850,000 in what would otherwise be good money after bad. Several local districts including Coatesville and Radnor are struggling with similar problems in multiple roof areas of their district.
Low-Sloped Roofs General Overviews Cafeteria/100 Wing, 600 Wing in Background Gym Roof Main Entrance/Auditorium Roof 500 Wing
Drainage/Ponding Concerns Cafeteria/Admin/Hallway 500 Wing 500 Wing Admin
Splits One of several repaired splits in the roof. A split repaired near roof drain on Auditorium Roof Another repaired split. Multiple repaired splits – MDS/212 Roof
Documentation of Splitting in a Tremco 3-ply BURmastic Roof Assembly Location: Elementary School in Radnor, PA The following short photo report documents the investigation of a long-term, on- going leak in an approximately 15 year old roof. The roof assembly is a common system assembled with 3 plies of composite ply membrane in cold-applied BURmastic adhesive. The source of the leak was discovered to be a split in the roof membrane, which formed over an insulation joint. It is a common problem in this specific roof system.
Repair Procedure Further cleaning and scraping of the gravel Once the area is cleaned and cleared of flood from the roof surface reveals the full extent of coat and gravel you can see how the split is the split. completely through the roof, a complete failure. Repairing the split – Flashing Bond (cold- High-tensile StressPly modified membrane process mastic) applied over the spilt. installed over split in bed of Flashing Bond mastic. 2 plies total installed for complete seal.
Reeceville Elementary Failure after Restoration One of several splits found in roof after Repair required at roof drain and beyond. restoration failure. Repair around another roof drain. Repair in corner around ventilator.
Additional Issues Faculty Roof/Gym Hallway Blisters and Closer view of blisters in roof Ponding Split at Expansion Joint Flashing Deterioration
Summary of Low Sloped Problems The roofs on the original school have no slope resulting in severe ponding water There is significant heat loss through the roof due to poor thermal value of the insulation which was typical of the time. The existing roof system type has a poor performance history that includes splitting in the long (machine direction). The current recommendation for resaturating the existing roof is not a remedy for the documented method of roof failure. Unfortunately, there is no remedy. Typical age related problems including flashing degradation, pitch pockets, expansion joints and other flashing also exist. The roof should be scheduled for replacement using tapered insulation to move water, better thermal insulation and a high performance multi-ply modified asphalt roof system with a non- prorated 30 year edge to edge warranty. Absolutely the lowest life cycle cost available
Metal Roof Condition Metal Roofs are in far better condition in terms of waterproofing than the low sloped roofs. They have a double hemmed seam which provides good waterproofing integrity. This is a steel panel so it will rust when scratched. There are several areas of the panel that have some rust evident The gutters were all galvanized steel without a Kynar coating and nearly 100% of the gutters have completely failed with the bottom completely rusted through allowing water to dump onto the Dryvit walls below. There are some uphill facing facia pieces that, combined with a very minimal overlap of the Dryvt finish is allowing water into the wall system. Another action item is stripping in the bottom of the metal to the rubber roof valley over the library which is an active and distracting leak Some of the trim that is used for metal roof flashing needs maintenance Overall no immediate issues outside of the gutter replacement and some remedial work on the edge metal and expansion joint trim.
Metal Roofs Overview 600 Wing Roof Library Roof Missing Fascia @ Library (now repaired) Rising Wall Between Library and 600 Wing
Metal Roof Finish Deterioration Rust Spots Scratches and Rust Scratch in Panel Damaged Snow Guards and More Rust
Gutter Failure Holes in Gutter – 600 Wing Courtyard Holes in Gutter – 600 Wing Above Library Roof Split in Gutter – 600 Wing Above 100 Wing Gutters are a poor quality galvanized with little protection against rust.
EFIS Condition The EFIS wall system is an acrylic cementitious material trowel applied over an expanded polystyrene insulation board. It is in poor condition due to a very light coating of the acrylic, no polyester fabric, and a lack of sill and other details on these walls throughout the 1999 addition Expansion and control joints have failed which is not unordinary given the age but need attention in the near term to protect the building Cracks in the EFIS itself are rampant. In the last few visits, cracks have emerged in areas we know for a fact were sound. This type of wall system is a economical selection during construction but has a high maintenance costs associated with it over time. Options include recoating it with a breathable masonry coating which we are already working on for problem areas such as rising wall over the 300 wing. Further study against industry standards is needed. A alternative solution would to recover the EFIS with metal wall panels and a rain screen system which is a permanent solution provided it is done correctly
EIFS (Dryvit) Walls Typical EIFS Wall Example of Typical Hairline Crack Crack in Control Joint Another Hairline Crack Example
Repair / Restoration Options We often restore roofs that are this age and do so with very good success. The first thing we look at when we go up on a roof is “Can it be saved?” In this case, anticipating the next split is impossible so repair is usually responding to a leak rather than preventing one Repair of flashing and expansion joint problems, pitch pockets and normal roof maintenance is feasible and will stop some of your problems. Reacting to leaks is a strategy that will never be dependable because you can’t anticipate the next split. The ponding water is a problem because it accelerates aging and if a leak occurs under standing water, there is no stopping it. We will help with any repair scope of work or respond to leaks for as long as necessary regardless of how many times we are called. We would not recommend restoration because of the tensile issues associated with splitting. That money is better spent elsewhere.
Replacement Options – Low Sloped Roofs Full Tear-off New Insulation (tapered to provide positive slope and drainage) Multi-ply Modified Roof System - Base layer is 1 ply 80 mil modified base - Cap ply is strong, high-tensile strength membrane that won’t Photo Caption split. Exceptional durability and low-maintenance. - Surfacing options include flood coat and gravel, factory applied mineral/granule, or field- painted Factory-manufactured, Code- compliant Roof Edge Metal Engineered Wind Uplift Calcs for System Attachment
Replacement Options – Low Sloped Roofs Gravel Surfaced Modified Roof – Riddle Gravel Surfaced Modified Roof – Riddle Village Village Gravel Surfaced Modified Roof - DAFB Gravel Surfaced Modified Roof - DAFB
Replacement Options – Low Sloped Roofs Mineral Surfaced Modified Roof –Cumberland Mineral Surfaced Modified Roof – Cumberland Tech Tech Mineral Surfaced Modified Roof – Upper Darby Gravel Surfaced Modified Roof – Upper Darby High School High School
Rising Wall Options Wall Repairs – Widener University Wall Recoating in Progress – Widener University Leaking Rising Wall to be Covered with New Newly Clad Rising Wall Wall Panels
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