ROOF MEMBRANE TYPES AND PV COMPATIBILITY

Purpose:

Adequate roof review is necessary for confirmation of PV installation feasibility. Without reviewing thoroughly and accurately, we will pull off jobs at install which will cause frustration among installers and customers.

TABLE OF CONTENTS:

1 | PV INCOMPATIBLE ROOF TYPES

STONE COATED STEEL TILE

FOAM ROOFS AT ANY TILT

1 | PV INCOMPATIBLE ROOF TYPES

This training centers around identifying PV compatible vs incompatible roof types. For identifying roof damages, complete Roof Damage

OVERVIEW

The following roof membrane types are incompatible for PV installations at ION. These roof types will automatically constitute a reroof:

Wood Shake Roof
Aluminum Shingle Roof
Stone Coated Steel Tile (Decra or Cal-Pac)
Clay Tile Roof (not to be confused with concrete tile)
Slate Tile

Site Survey: Please identify the correct roof membrane type in FIELDPRO.

Design & Engineering: Flag for a reroof if you see any of the incompatible roof types listed in this chapter.

Light Reach (PPA) Disqualified Roof Types:

Clay Tile Roof
Metal Shingle (including asphalt and stone coated)
Wood and Cal Shake
Tar & Gravel
Copper or Tine Metal
Cal Pac
SIP

WOOD SHAKE

Wood shake is tricky to qualify and difficult to install on without damaging. ION policy dictates that we will not install on this type of roof under any circumstance. Here's a quick overview of what the issues are:

Vulnerable to pests, mold and fire
Life span depends heavily on care.
- Can last as little as 15 years

For this reason, it is a huge liability to install on these roofs.

UNDERLYING WOOD SHAKE

Hidden under the skipped lumber sheathing and can be easily missed. Don’t miss this.

Make sure to also look out for underlying wood shake!

This is often located under comp shingle roof types on older homes.
Surveyors must check for this from within the attic. Its hidden and cannot be easily seen from the exterior of the home.

Site Survey: Please identify the correct roof membrane type in FIELDPRO.

Design & Engineering: Flag for a reroof if you see a roof that appears to be wood shake.

METAL SHINGLE

Installing on this roof membrane type usually requires a stanchion or lag bolt with L-foot that press the tile down too much and will damage the roof. ION has chosen not to inastall on this roof under any circumstance for liability reasons.

Metal shingle is easy to identify:

Looks like thin metal sheets but designed as a shingle.
Not to be confused with sheet metal type roof membranes

Site Survey: Please identify the correct roof membrane type in FIELDPRO.

Design & Engineering: Flag for a reroof if you see a roof that appears to be metal shingle.

CLAY TILE

This type of roof is often seen in the Southwest, but could be anywhere. It is not to be confused with concrete tile. Concrete tile is PV compatible, so it is important to distinguish between the two.

here are a few reasons why ION does not install on clay tile roofs:

Very brittle / breakable.
- This makes the act of installing very difficult because tiles can breaker under the weight of installers with their gear.
Clay can be expensive and technical to replace.

Compare: Which photos show concrete tiles and which show clay in the photos below?

Indications that you’re looking at a clay roof:

Very distinct casting seams
Smooth appearance
Vibrant orange/terracotta color

Concrete or Clay?

This is definitely clay.

Generally, casting lines like this do not appear on concrete tiles.
Also note the coloring. The color of this tile is exactly the same as common terracotta pots used for planting.
- That's because it's the exact same clay used.

Concrete or Clay?

This is concrete.

The edges are rough.
The texture appears to be more grainy than that of clay.

Concrete or Clay?

This is concrete.

The edges are rough.
The texture appears to be more grainy than that of clay.
These tiles are also much thicker than a typical clay tile.

Concrete or Clay?

This is most likely clay

The texture is very smooth
The coloring is very consistent

Concrete or Clay?

This is definitely clay

"C" shaped tiles are almost always clay.
- This style of tile is not generally manufactured using concrete.
Note the coloring here is somewhat inconsistent, though, this roof appears to be somewhat weathered which would account for differences in coloring.

Site Survey: Please identify the correct roof membrane type in FIELDPRO.

Design & Engineering: Flag for a reroof if you see a roof that appears to be clay tile.

SLATE TILE

The issues faced with slate tile are identical to that of clay tile. They are brittle and expensive to fix. For this reason, ION will not install on this type of roof.

Again, here are a few reasons that slate roofs are not considered PV compatible here at ION:

Very brittle / breakable.
Slate can be expensive and technical to replace.
Identify by looking for jagged edges and green tones in some of the tiles.

Site Survey: Please identify the correct roof membrane type in FIELDPRO.

Design & Engineering: Flag for a reroof if you see a roof that appears to be slate tile.

STONE COATED STEEL TILE

Stone coated steel presents similar issues as metal shingle. You'll notice that all disqualifications are mainly to do with similar liability issues.

Here is some basic info you should know about stone coated steel tile:

AKA “Decra Tile” or “Cal-Pac”
Looks similar to concrete tile but “hollow”
Can be nailed or screwed down. Screws / Nails can be hidden.

Stone coated metal tile can come in a variety of different styles:

Site surveyors should be able to easily identify these tiles:

Light weight and hollow
Metallic undersurface
Fastened with screws or nails as seen in the middle photo

Site Survey: Please identify the correct roof membrane type in FIELDPRO.

Design & Engineering: Flag for a reroof if you see a roof that appears to be stone coated steel tile.

FOAM ROOFS AT ANY TILT

Some buildings use spray-foam covering to both waterproof and windproof the top of the building. Foam is unusable due to the damage the roof mounting would cause to it. The roof material must be replaced with something our mounting systems can use, or the entire roof section is not viable.

2 | COMPATIBLE ROOF MEMBRANE TYPES

OVERVIEW

The following roofing materials are compatible for PV installations at ION:

Composition Shingle
Concrete Tile
Sheet Metal
Flat Roof Membranes

Site Survey: Please identify the correct roof membrane type in FIELDPRO.

Design & Engineering: note that we still need to flag any roof damage and make sure the condition of the roof is suitable for PV on these PV compatible roofs. Complete Roof Damage to learn more about what to look out for.

COMPOSITION SHINGLE

Comp shingle is the most common roof type seen on most homes. If you see comp shingle, you don't need to worry about an automatic disqualification. Be aware that shingles come in a variety of shapes and quality, mainly we're looking for flat shingles with granules. Please also be aware that we still need to call out re-roofs and repairs for wear and damage on compatible roof types. A roof being made of a PV compatible material does not automatically mean that it is in suitable condition to install solar. Be vigilant and flag damage and wear as needed.

Quick facts about composition shingle:

AKA Comp Shingle or Asphalt Shingle
Majority of homes will have shingles.

Basic shingle types:

3 tab
- 25 years
Architectural
- 30 years
Presidential and other premium shingles
- 30+ years

These are all PV compatible and despite their differing appearance, All types of comp shingle use the same mounting hardware

Site Survey: Please identify the correct roof membrane type in FIELDPRO.

Design & Engineering: note that we still need to flag any roof damage and make sure the condition of the roof is suitable for PV on these PV compatible roofs.

CONCRETE TILE

Concrete tile will be the most common roof membrane type in some markets such as Nevada, New Mexico and Arizona. The main thing to look out for is clay tile. Concrete tile is often made to approximate the form of clay tile so it can be a little confusing some times. Again, make sure to look closely to ensure the correct call out. You don't want to miss a needed re-roof.

Quick facts about concrete tile:

Will Be S-Type, W-Type, or Flat-Type
Located all over the US but mostly in the southwest regions.
Has Concrete granules / texture. Look up closely at photos if uncertain.
Not to be confused with Clay Tile. Usually not a vibrant orange color, but that's not a hard fast rule.

These are all PV compatible and despite their differing appearance, All types of concrete tile use the same mounting hardware

Site Survey: Please identify the correct roof membrane type in FIELDPRO.

Design & Engineering: note that we still need to flag any roof damage and make sure the condition of the roof is suitable for PV on these PV compatible roofs.

SHEET METAL

Sheet metal is popular all over the place. it is a very durable roof membrane type as long as the finish isn't damaged, there is low probability of significant wear. This roof type generally requires a lot less scrutinizing when screening for damage in comparison to shingle and even tile roofs.

Quick facts about sheet metal roofs:

Standing Seam Type
Trapezoidal Type
Corrugated (wave) Type.

If there is any rust or damage, please fill in the “Exterior Roof - Metal Roof - Is there any roof damage present?” question in the site survey FIELDPRO template.

These are all PV compatible and despite their differing appearance, All types of comp shingle use the same mounting hardware

Site Survey: Please identify the correct roof membrane type in FIELDPRO.

Design & Engineering: note that we still need to flag any roof damage and make sure the condition of the roof is suitable for PV on these PV compatible roofs.

FLAT ROOF MEMBRANE

There are many types of flat roof membranes. For the most part, all are compatible with PV installations at ION Solar. Most of these will default to a balast type system rather than traditional mounting standoffs. Rolled comp and TPO are still compatible with traditional mounts though.

Here's a list of the most common flat roof types:

TPO
EPDM
Rolled Composition Asphalt (aka Modified Bitumen)
Tar and Gravel

Site Survey: Please identify the correct roof membrane type in FIELDPRO.

Design & Engineering: note that we still need to flag any roof damage and make sure the condition of the roof is suitable for PV on these PV compatible roofs.

2 | QUIZ

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