Roofing System Guide

This selection guide indicates the compatible Andek product for use on a particular type of roof. Individual situations may require an alternative product or system.

Roof Type Primer Basecoat Finish Coat Reinforcement
Acrylic over PUF No Polaroof AC Polaroof AC Urethane caulk where necessary

The condition of the polyurethane foam (PUF) should be examined to determine its adhesion to the substrate and inter-layer adhesion. Acrylic coated polyurethane foam may be re-coated using an acrylic coating such as Polaroof AC. Any damage to the P.U.F. should either be cut out and re-foamed or be repaired using a urethane caulk such as PSI 803, and any exposed foam should be primed with a P.V.C./acrylic primer such as Polaprime 2.

Roof Type Primer Basecoat Finish Coat Reinforcement
Asphalt, Smooth No Roofdx Super & Roofab Polaroof RAC or Silver Film Roofab overall installed into basecoat
Asphalt, Stones Buildkote Roofdx Super & Roofab Polaroof RAC or Silver Film Roofab overall installed into basecoat
Asphalt, Stones Buildkote Roofdx Super & Roofab Polaroof RAC or Polaroof NW Roofab overall installed into basecoat
Coal Tar, Stones Buildkote Roofdx Super & Roofab Polaroof RAC or Silver Film Roofab overall installed into basecoat
Coal Tar, Smooth No Roofdx Super & Roofab Polaroof RAC or Silver Film Roofab overall installed into basecoat

Built-up roofs (B.U.R.) may be asphalt (crude oil derivative) or coal tar (by-product of steel production from coal).  Although similar in many respects, they are quite different chemically.  Successful repair and restoration of these roofs will normally depend on accurate analysis of their chemistry, as repair with incompatible materials will lead to failure.  A moisture-cure urethane coating such as RoofdX Super may be used over either asphalt or coal tar built-up roofing.  If there are any stones remaining on the roof that cannot be removed, a rubberized foundation coat such as Andek Buildkote may be used to improve adhesion.  A high strength polyester fabric such as Roofab is used to reinforce the urethane coating and form a flexible, waterproof, chemical-resistant membrane.  A solar reflective coating such as Silver Film or Polaroof NW should be used to reflect heat, therefore extending the life of the roof and lowering energy consumption of the building.

Roof Type Primer Basecoat Finish Coat Reinforcement
Concrete Polaprime 21 Polaroof RAC NW ‘Z’ Grade Roofab & Polajoint

After the concrete has been treated and cleaned, a penetrating primer such as Polaprime 21 may be applied to remove the surface porosity and seal any rust stains from rebar corroding beneath the surface.  Joints are filled with an epoxy polyurethane sealant, Polajoint, and cracks are bridged and reinforced with polyester fabric such as Roofab and a moisture-cure polyurethane coating such as Polaroof RAC.  A basecoat of moisture-cure polyurethane coating such as Polaroof RAC is applied overall, followed by a topcoat of a synthetic rubber-based coating such as NW ‘Z’ Grade in an appropriate color.

Roof Type Primer Basecoat Finish Coat Reinforcement
EPDM No Polaroof RAC Polaroof RAC Roofab on seam

E.P.D.M. is also known as rubber roofing but is very different from other materials referred to as SBS rubber roofing. All repairs are made with Roofab polyester fabric saturated with Polaroof RAC moisture-cure urethane that will set together to form a reinforced membrane. After repairs have been accomplished, a basecoat and topcoat of Polaroof RAC moisture-cure urethane coating is applied to provide a protective, waterproof, energy-reflective finish. The composite membrane formed by application of the Polaroof RAC is stronger and more durable than the original EPDM roofing alone. In this way way, a 60 mil EPDM membrane becomes a 90 mil EPDM/Polyurethane composite membrane.

Roof Type Primer Basecoat Finish Coat Reinforcement
GRP No Polaroof RAC or Polaroof NW Polaroof RAC or Polaroof NW Polyurethane caulk where necessary

G.R.P. (glass reinforced polyester) is also known as fiberglass.  Technically, it is a plastic composite, either molded or formed in situ.  The gel coat on the surface chalks and erodes to become porous, allowing water to penetrate the other layers.  Repairs may be made with a urethane caulk such as PSI 803 and a basecoat of either Polaroof RAC, moisture-cure urethane, or Polaroof NW, ethylene elastomer coating, to seal the gel coat.  A finish coat of either Polaroof RAC metallic polyurethane, or Polaroof NW elastomeric coating in any color, may be applied to protect the surface.

Roof Type Primer Basecoat Finish Coat Reinforcement
IRMA No Roofdx Super Roofdx Super Roofab overall and suitable protection board

These types of roofs have the waterproof membrane buried beneath a traffic surface that may consist of layers of drainage mat, insulation, pavers, and pedestals. A tough, damage-resistant, waterproof membrane is produced by the combination of RoofdX Super, iron modified polyurethane, and Roofab polyester reinforcement.  After the membrane has cured to achieve sufficient strength, it may be buried beneath the appropriate combination of paving materials.

Roof Type Primer Basecoat Finish Coat Reinforcement
Factory Finished, Exterior Fastened, No Rust No Polaroof AC Polaroof AC Roofab on seams, Polaroof RAC + K Catalyst pretreatment on fasteners
Factory Finished, Exterior Fastened, Some Rust Polaprime DTM Polaroof AC Polaroof AC Roofab on seams, Polaroof RAC + K Catalyst pretreatment on fasteners
Factory Finished, Heavy Rust Polaprime 21 Polaroof NW Polaroof NW Roofab on seams, Polaroof NW + K Catalyst pretreatment on fasteners
Galvanized, Fastened, No Rust Polaprime DTM Polaroof AC Polaroof AC Roofab on seams, Polaroof RAC + K Catalyst pretreatment on fasteners
Galvanized, Fastened, Patchy Rust Polaprime DTM Polaroof NW Polaroof NW Roofab on seams, Polaroof NW + K Catalyst pretreatment on fasteners
Galvanized, Fastened, Heavy Rust Polaprime 21 Polaroof RAC Polaroof RAC or Polaroof NW Roofab on seams, Polaroof RAC + K Catalyst pretreatment on fasteners
Galvanized or Factory Finished, Heavy Industrial Environment Polaprime 21 Polaroof RAC Polaroof RAC-OZ Roofab on seams, Polaroof RAC + K Catalyst pretreatment on fasteners
Galvanized or Factory Painted, Severe Industrial Environment Polaprime 21 Polaroof RAC-OZ Polaroof RAC-OZ Roofab on seams, Polaroof RAC-OZ + K Catalyst pretreatment on fasteners
Copper No Roofdx Copper Roofdx Copper Roofab on seams and penetrations
Simulated Gold No Roofdx Gold Clearcoat FP Roofab on seams and penetrations

The treatment of metal roofs will vary, depending on the condition of the roof and the environment in which it exists.  If it is factory painted and in good condition with no rust, no primer would be necessary.  If patches of rust are present, these areas should be cleaned and spot primed.  If rusting is extensive and covers large areas, the entire roof should be primed.  If the roof is galvanized, whatever its condition, it should be primed.  The primer would be either an air dry PU Primer such as Polaprime DTM or a moisture-cure urethane primer such as Polaprime 21.  The basecoat and finish coat would be the same material and would vary, depending on roof design and environmental exposure.  Most metal roofs would be coated with a high quality elastomeric acrylic coating such as Polaroof AC.  If the roof is flat or has an extremely low slope, then a solvent-based ethylene elastomer coating such as Polaroof NW would be used.  In an industrial environment, a metallic polyurethane coating such as Polaroof RAC would be used; and in a severe industrial environment, an oxazolidone polyurethane coating such as Polaroof RAC-OZ would be used.  If a copper or gold finished appearance is required, then a synthetic rubber/resin compound with metal flake dispersion such as RoofdX Copper or RoofdX Gold would be used.  All of these coatings may be reinforced with Roofab polyester fabric to make repairs to the seams, laps, and penetrations.  Fasteners are sealed with a pre-treatment of the same material as is used for the basecoat and repair.

Roof Type Primer Basecoat Finish Coat Reinforcement
Lead Coated Metal, Standing Seam, No Erosion No Polaroof RAC Roofdx SL Polaroof RAC + K Catalyst at seams & perforations
Lead Coated Metal, Standing Seam, Patchy Erosion Roofdx Super Polaroof RAC Roofdx SL Polaroof RAC + K Catalyst at seams & perforations
Lead Coated Metal, Standing seam, Heavy Erosion Roofdx Super Polaroof RAC Roofdx SL Polaroof RAC + K Catalyst at seams & perforations

The treatment of all metal roofs will vary, depending on the condition of the roof and the environment in which it exists. If the lead coating is in good condition with no erosion, no primer would be necessary. If patches of erosion are present, these areas should be cleaned and spot primed. If erosion is extensive and covers large areas, the entire roof should be primed. The ideal primer would be a moisture-cure urethane coating such as Roofdx Super.

Repairs are accomplished using Polaroof RAC reinforced with K Catalyst. After repairs are complete, a coat of Polaroof RAC, moisture cure polyurethane coating is applied. The topcoat is a stainless steel flake reinforced polyurethane coating such as a Roofdx SL applied dimensionally to re-create a hot lead dipped finish.

Roof Type Primer Basecoat Finish Coat Reinforcement
Modified Asphalt, Smooth No Polaroof RAC Polaroof RAC or Polaroof NW Roofab over seams and penetrations
Modified Asphalt with Granules No Polaroof RAC Polaroof RAC or Polaroof NW Roofab on seams and penetrations

The surfaces of these roofs are either granulated or coated, eventually the granules or coating begins to wear off. Deterioration begins in the form of surface reticulation or “alligatoring.” Modified asphalt roofs are sometimes referred to as “rubber roofs,” but are very different to E.P.D.M., which is more normally referred to as a “rubber roof.” There are two basic types of modified asphalt roofs, A.P.P. (atactic polypropylene), which is applied by torching down with an open flame, or S.B.S. (styrene butadiene styrene), which is glued down with an adhesive. Repairs may be made with Polaroof RAC saturated into Roofab polyester fabric. A basecoat of Polaroof RAC polyurethane coating is used to seal the surface of the modified asphalt, and a topcoat of either Polaroof RAC (silver) or Polaroof NW (in any color) is used to complete the protection.

Roof Type Primer Basecoat Finish Coat Reinforcement
PVC (Reinforced) No Polaroof RAC Polaroof NW Roofab where necessary

P.V.C. (reinforced) roofs must be cleaned thoroughly to remove all chalk, dirt, and debris.  Seams, penetrations, and damaged areas should be repaired and reinforced with Polaroof RAC polyurethane coating, saturated into Roofab polyester fabric.  A basecoat of Polaroof RAC polyurethane coating is used to seal the surface and protect the integral reinforcement which, when exposed, may channel moisture through the seams to the fasteners.  A topcoat of Polaroof NW or Polaroof AC in any color will complete the protection and restoration.  Polaroof AC (acrylic coating) is used on all sloping or vertical surfaces, and Polaroof NW (ethylene elastomeric coating) on all flat or ponding surfaces.

Roof Type Primer Basecoat Finish Coat Reinforcement
Polyurea No Polaroof RAC Wearcoat 44 Roofab where needed

Polyurea may be repaired with Polaroof RAC polyurethane coating and Roofab polyester fabric if splits or damage have occurred. In the case of excessive wear that has reduced the thickness of the polyurea, a basecoat of Polaroof RAC polyurethane coating may be used to restore the original thickness. A topcoat of Wearcoat 44 aliphatic polyurethane coating, in any color, is used to provide complete protection of the polyurea and an aggregate broadcast may be incorporated to enhance traction for rooftop foot traffic.

Roof Type Primer Basecoat Finish Coat Reinforcement
Slate – All Types Polaprime 2 Polaroof AC Polaroof AC (Slate color) Urethane caulk where necessary

Slate is mainly vulnerable around the edges, where capillary action draws water into its laminations, allowing freeze-thaw damage.  Impact damage and nail tiredness from wind agitation also hastens its demise.  Gaps may be filled with urethane caulk and broken slates repaired with Andek 950 polyurethane used as an adhesive.  The edges of the slates are sealed with Polaprime 2 PVC/acrylic primer, and two coats of Polaroof AC acrylic coating are brushed over and around the slates to provide a waterproof and wind-resistant seal.

Roof Type Primer Basecoat Finish Coat Reinforcement
Tile (Concrete) Polaprime 2 Polaroof AC Polaroof AC (Tile Color) Urethane caulk where necessary

Concrete tile is weakened and eroded by acid rain and, it is vulnerable to freeze-thaw deterioration, impact fracture, and salt accelerated weathering.  Urethane caulk is used to seal gaps, and Andek 950 is used as an adhesive to repair broken tiles.  The tile surfaces are primed and sealed with Polaprime 2 PVC/acrylic primer, then two coats of Polaroof AC, acrylic coating are applied by brush or spray to completely encapsulate the roof with a waterproof, protective finish in a color to match the tile.

Roof Type Primer Basecoat Finish Coat Reinforcement
Tin-Colonial Style Painted, Good Condition No Polaroof AC Polaroof AC Roofab on horizontal seams & perforations
Tin-Colonial Style Painted, Slight Rust Polaprime DTM Polaroof AC Polaroof AC Roofab on horizontal seams, penetrations & perforations
Tin-Colonial Style Painted, Significant Perforations Polaprime 21 Polaroof AC Polaroof AC Roofab saturated into basecoat over entire roof

Tin roofs are ferrous, with a tin/lead alloy coating.  There are often many layers of paint that have been used to protect them.  Surface preparation will include removal of all loose rust and layers of loose paint.  Polaprime 21 or Polaprime DTM is used to seal and encapsulate tightly adherent rust.  Roofab polyester fabric is laid into a wet coat of Polaroof AC acrylic coating and thoroughly saturated with a second coat to seal perforations and reinforce weak areas.  Two coats of Polaroof AC acrylic coating in an appropriate color are then applied to provide a waterproof, protective layer and restore the appearance and function of the roof. An additional coating with a fluoropolymer urethane such as Clearcoat FP will add an additional protective layer to significantly extend the lifespan of the restored roof.

Roof Type Primer Basecoat Finish Coat Reinforcement
Reinforced TPO No Polaroof RAC Polaroof NW Roofab where necessary

TPO (reinforced) roofs must be cleaned thoroughly to remove all chalk, dirt, and debris.  Seams, penetrations, and damaged areas should be repaired and reinforced with Polaroof RAC polyurethane coating, saturated into Roofab polyester fabric.  A basecoat of Polaroof RAC polyurethane coating is used to seal the surface and protect the integral reinforcement which, when exposed, may channel moisture through the seams to the fasteners.  A topcoat of Polaroof NW or Polaroof AC in any color will complete the protection and restoration.  Polaroof AC (acrylic coating) is used on all sloping or vertical surfaces, and Polaroof NW (ethylene elastomeric coating) on all flat or ponding surfaces.

Roof Type Primer Basecoat Finish Coat Reinforcement
Transite 1-1/2″ PUF Polaroof AC Polaroof AC PUF accomplishes this

Transite and other fiber-reinforced cementitious composite roofing becomes weakened by acid rain, freeze-thaw, and microbiologically accelerated weathering.  These roofs may become weakened to the point that it is unsafe to cross them without duckboards.  Spray-applied polyurethane foam, at a minimum of 1-1/2” thick, provides reinforcement and improves the structural integrity of the roof.  Two coats of a high quality acrylic coating such as Polaroof AC will protect and seal the roof while also providing a layer of fire protection.

Roof Type Primer Basecoat Finish Coat Reinforcement
Silicone coated PUF No Polaroof RAC Polaroof RAC Urethane caulk where necessary

The condition of the polyurethane foam (PUF) should be examined to determine its adhesion to the substrate and substrate and inter-layer adhesion. Silcone coated PUF may be re-coated with a moisture-cure polyurethane coating such as Polaroof RAC provided that the silicone has weathered at least 2 years. Any damage to the PUF should be either cut out and re-foamed or repaired using a urethane caulk such as PSI 803.

Roof Type Primer Basecoat Finish Coat Reinforcement
Urethane Foam, New No Polaroof RAC or Polaroof RAC-OZ Polaroof RAC or Polaroof RAC-OZ No

New urethane foam should be protected by a high quality polyurethane coating to provide a waterproof, fire-retardant, solar-reflective and hail-resistant finish.  Polaroof RAC provides this, with approvals from both Underwriters Laboratories and Factory Mutual, so that the best quality standards are maintained.  Additional chemical resistance around stacks, vents, and grease traps is provided by using OZ Catalyst to convert Polaroof RAC to Polaroof RAC-OZ oxazolidone coating.

Roof Type Primer Basecoat Finish Coat Reinforcement
Wet Roofs No Rubberkote 1047 Rubberkote 1047 Roofab where necessary

It is often necessary to make emergency repairs during inclement weather.  The repair material should provide immediate waterproofing and continue to set and gain strength in all weather conditions.  Rubberkote 1047 is a synthetic rubber-based sealant and coating that is reinforced with Kevlar.  Additional reinforcement is achieved by incorporating Roofab polyester fabric into the Rubberkote 1047.  Unlike most emergency repair materials that need to be removed before permanent repairs are made, Rubberkote 1047 will be effective for five years or more and may be painted without staining.

Repairs made with Rubberkote 1047 may be protected with an appropriate Andek coating system such as Polaroof RAC and Roofab, Polaroof RAC/Polaroof NW, etc. Application of a coating system over the Rubberkote 1047 will significantly extend the lifespan of the entire roof.

Roof Type Primer Basecoat Finish Coat Reinforcement
Wood Shingles or Wood Shakes Polaprime 2 Andek Firegard Andek Firegard No

Wood shingles and shakes deteriorate from weathering caused by sunlight, rain, and fungal attack.  They are also vulnerable to destruction by fire.  Polaprime 2 PVC/acrylic primer soaks into the wood to seal it and restore its strength.  A waterproof, fungus-resistant, fire-resistant coating such as Polaroof Firegard P.V.C. coating, applied in two coats, provides a protective layer that maintains the desired appearance in color and texture.