This document establishes that the product is no longer manufactured. Discontinued in 2001 and dimensionally incompatible with the Cambridge sold today: the old Imperial shingle ran 39 3/16″ × 14¼″ at a 6⅛″ exposure, the current Metric one 40⅞″ × 13¾″ at 5⅞″. IKO also rejects trimming new shingles to fit.
Discontinued IKO · Roofing · 2001 · 1 page
New vs Old Shingle Compatibility — IKO Cambridge 25
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New vs Old Shingle Compatibility — IKO Cambridge 25
Issued by IKO. Published here complete — no summary standing in for the document, no email required.
Issued by IKO. 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
A carrier cannot direct you to buy something that is not sold. Once the product is off the market, the question stops being "can this be repaired" and becomes "can this building be restored with materials of like kind and quality" — which is a very different question, and one the carrier has to answer.
- 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 IKO documents
IKO Cambridge
IKO’s Warranty Services Department confirms Cambridge changed dimensions in 2002, making pre- and post-2002 shingles incompatible on the same plane — and that the colours changed too.
IKO Cambridge vs. Dynasty
IKO’s Codes and Compliance Officer on mixing two current IKO products, never mind old and new. IKO also disclaims responsibility where a mixed repair is performed.
IKO Gentry (3-tab)
The Gentry 3-tab (36″ × 12¼″, 5⅛″ exposure) is discontinued with no replacement — IKO no longer manufactures a standard-size three-tab at all. The only three-tab it still makes, Marathon Plus AR (39⅜″ × 13¼″, 5⅝″), is expressly incompatible.
IKO Marathon Plus AR vs. Gentry 25 AR
IKO states the two three-tabs cannot be mixed, and gives the reason in performance terms rather than appearance.
IKO Cambridge · Dynasty · Armourshake · Ultra HP colours
Colourways retired effective 2022: Cambridge Aged Redwood, Dynasty Pacific Rim, Armourshake Western Redwood, H&R 12 Aged Redwood and Pacific Rim, and Ultra HP / Ultra HP IR Aged Redwood — plus low-slope base products.
IKO underlayment laps
IKO requires underlayment to wrap a minimum of 6″ over hips and ridges onto the adjoining slope. A single slope on an IKO roof cannot be replaced in isolation without opening the underlayment on the slopes beside it.
Other manufacturers saying the same thing
Atlas Chalet
Atlas discontinued the Chalet 30-year laminated shingle in mid-2010 and replaced it with the Pinnacle HP line. Chalet went onto tens of thousands of Georgia homes, and it is the single most common discontinued-shingle dispute in this market.
Atlas Chalet
Atlas’s follow-up letter goes further than the discontinuation itself: the Chalet’s proprietary design and physical size differ from current production, so combining old and new raises ASTM compliance problems.
Atlas GlassMaster
Atlas Roofing Corporation confirms in writing that the GlassMaster shingle is no longer manufactured.
Atlas StormMaster Slate
Discontinued effective January 1, 2023. Atlas did not just retire the product — it stated on the record that nothing else in the market matches it.
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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