This document is the manufacturer stating that its own products cannot be combined on one building. Mixing AR and non-AR shingles produces two defects: an immediate colour difference, and a slower one as algae grows on only half the roof.
Do-not-mix CertainTeed · Roofing · 2015 · 1 page
Applying or Mixing Algae-Resistant (AR) Shingles with Non-AR Shingles
In their own words
CertainTeed does not recommend mixing AR with non-AR shingles on the same roof plane… an unsightly, patchwork roof after a few years.
CertainTeed — Applying or Mixing Algae-Resistant (AR) Shingles with Non-AR Shingles, 2015
That sentence is not our characterisation of the manufacturer’s position. It is the manufacturer’s position, in the document below, which you can read yourself in about a minute.
Get the document
Applying or Mixing Algae-Resistant (AR) Shingles with Non-AR Shingles
Issued by CertainTeed. Published here complete — no summary standing in for the document, no email required.
Issued by CertainTeed. Held in this firm’s reference library; not published elsewhere. Homeowner-identifying details, where a letter was addressed to a particular property, are blacked out — nothing else is altered, and no operative text is ever redacted.
What to do with it
This is the argument carriers least expect, because it does not come from you. When the manufacturer says two of its own products may not share a roof, a repair that combines them is not a cheaper way of doing the job — it is a defective installation, and the party who directed it owns the outcome.
- You have the manufacturer’s document. That part is finished. Most homeowners never get this far, and it is the step a carrier cannot argue with — it is not your opinion, it is the company that made the product.
- Put it in writing, to the adjuster, with the claim number. Attach the document and ask one specific question: name the exact replacement product — manufacturer, line, colour, dimensions, exposure, nail zone, sealant design, supplier, quantity available locally — and who will answer for the repair if it fails. Vague answers are the whole game; a specific question ends it.
- Get the position on the record before anything gets installed. Once a mismatched or incompatible repair is on the building, you are arguing about something already done.
If you want the second and third steps handled by someone who does this for a living, that is what we are for — and the review costs nothing. If you would rather do it yourself, the document above is yours either way. That is the point of publishing it.
Related documents
Other CertainTeed documents
CertainTeed discontinued product register
CertainTeed’s own master register of permanently discontinued and modified lines — the first place to look if your roof is CertainTeed.
CertainTeed Landmark and related lines
Even where the product name has not changed, CertainTeed identifies three conditions that defeat a partial repair on an aging roof: the older shingles have lost pliability, the granule blend has been reformulated, and lines such as Landmark converted from English to metric dimensions.
CertainTeed roof repair guidelines
CertainTeed’s own repair standard rejects reusing shingles and forbids intermixing metric and English (standard) sizes on one roof. Building codes require installation to follow the manufacturer’s instructions — which makes this document a code argument, not just a preference.
CertainTeed Independence AR · Patriot AR
Independence AR and Patriot AR discontinued across the South Atlantic region excluding Alabama, plus colour deletions across Cedar Crest AR (Chaparral Cedar, Saddle Brown, Slate Gray) and Highland Slate AR (Saddle Brown).
CertainTeed Independence Designer
The manufacturer’s bulletin for a discontinued premium shake-look shingle — Shangle design, 300 lbs. per square, UL Class A, Class 1 impact rated. When the original product is gone, this is the specification a proposed substitute has to be measured against.
CertainTeed Independence Designer
The full original colour range for a shingle you can no longer buy: Burnt Sienna, Charcoal Black, Colonial Slate, Cottage Red, Driftwood, Georgetown Gray, Hamilton Blue, Heather Blend, Hunter Green, Weathered Wood.
Other manufacturers saying the same thing
Atlas Pinnacle
Three separate dimensional eras of the same product name. Pre-2013 Pinnacle measured 38¼″ × 13⅛″ at a 5⅝″ exposure; 2013–2017 measured 39⅜″ × 14″ at 6″; 2017-on measures 42″ × 14″ at 6″. A “Pinnacle roof” tells you almost nothing until you know which era.
Atlas Pinnacle · StormMaster Shake
Effective July 2, 2013 Atlas changed the dimensions of both lines — from 38¼″ × 13⅛″ to 39⅜″ × 14″ — and stated plainly that the two generations cannot share a roof deck.
Atlas Pinnacle Pristine
Atlas states a do-not-mix condition between the original Pinnacle Pristine and every later version. It no longer manufactures a shingle at a 5⅝″ exposure or 39⅜″ length, and the current HP42 cannot be installed on the earlier roof.
GAF Timberline HD vs. Timberline HDZ
The companion to the discontinuation notice, and the one that closes the loop: the successor product cannot be used to patch the old one. GAF withdraws warranty coverage where the two are mixed.
The rule this document serves
Your policy promises repair or replacement with material of like kind and quality. That is a replacement-cost and indemnity obligation, not an appearance theory — and it is why “matching” is the carrier’s word, not the policy’s. Where the installed product cannot be bought, or cannot be combined with what is still sold, the covered building cannot be restored to like kind and quality by patching it, and that is true before anyone argues about how it looks. The full doctrine, and the other 125 documents, are on the discontinued materials hub.
You have the manufacturer's document. The next part is the argument. Handing a carrier a technical bulletin and getting it honoured are two different jobs. The case review is free, and you pay nothing unless we recover.
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