Read the profile sheet.
Then read the warranty.
A trim quote is a list of numbers and letters, and every one of them means something. The WM number with its two fractions. The material letter and the glue class. The paint window, and the warranty with its list of covered words. None of it is hard. Here is how to read it slowly, with a real lifetime PVC warranty as the example.
Six things on a trim spec, and where each one comes from.
The profile number. WM numbers are the standard patterns of the Moulding and Millwork Producers Association; Metrie, Woodgrain, and the mills print their own numbers on their own profiles. Either way the number is a shape. Beside it are two fractions, thickness first, then width: WM623, 9/16 x 3-1/4. Then the letters for what it is made in. On the Wholesale Millwork sheet those are P primed, S solid, O oak, V PVC, M MDF. On Metrie's they are MDF/UL, PFJ for primed finger-joint pine, PIN for solid pine. Same idea.
Moisture content. Woodgrain defines it as the weight of the water in the wood as a percentage of the oven-dry weight. What the literature gives you is not a number for the bundle but a rule: Metrie's 3 days in the room before nailing, and Woodgrain's two adhesive classes for finger-joint stock, dry-use under 16 percent and wet-use at 16 and above. Ask which class the exterior finger-joint on the quote is glued with. If nobody knows, it is dry-use until proven otherwise.
Exterior rating. Trim has no code report. It has a maker's statement. VERSATEX prints a density of 0.55 g/cm³ (ASTM D792) and water absorption under 0.5 percent (ASTM D570) and says at or below grade is fine. TruExterior says ground and masonry contact are fine and cut ends need no primer. LP prints clearances instead: 6 inches to grade, 1 inch off horizontal surfaces, 3/8 inch off brick with flashing, seal every cut. A board with none of those statements is an interior board.
The paint window. Pre-primed exterior trim carries a deadline for the finish coat, and the deadline is in the warranty conditions: LP 180 days, TruExterior 150 days, AZEK PaintPro 180 days from the day it sees sun. Unprimed PVC has no deadline and a color rule instead, an LRV of 55 or higher for AZEK and 50 for VERSATEX, with vinyl-safe or heat-reflective paint for anything darker.
Expansion and the temperature rule. For PVC: AZEK allows 1/8 inch per 18 feet, properly fastened, more on dark colors. VERSATEX says only long runs of three or more 18-foot boards need managing, and wants long runs put up when the boards and the air are about 60 to 70 degrees; under 40, pre-drill. Both say glue the joints and fasten to the schedule rather than leave gaps.
MDF and water. Woodgrain says MDF absorbs water and can swell, warp, or disintegrate, and not to put it where it may get wet. No number is published, so the rating is a location, not a percentage.
Which number, and which two fractions. Which letter. Which glue class on the exterior finger-joint. What is the paint deadline, and is it on the schedule. What is the LRV of the PVC color. What day of the week do the sticks go in the house.
| Line on the sheet | Where it comes from | What it tells you | Look for |
|---|---|---|---|
| Profile number | WMMPA WM series; maker numbers (Metrie, Woodgrain, Legacy L series) | The shape, so it can be matched later | A number with its thickness, width, and material letter on every line |
| Moisture content | Woodgrain glossary definition; Metrie 3-day acclimation; Woodgrain adhesive classes (16 percent EMC line) | How much the stick will move after it is nailed | A meter reading, a dry bundle, and 3 days in the room |
| Exterior rating | VERSATEX ASTM D792 / D570; TruExterior ground-contact statement; LP clearance table | Where the board can live | A ground-contact statement, or a clearance table you will follow |
| Primer and paint window | LP 180 days; TruExterior 150 days; AZEK PaintPro 180 days; AZEK and VERSATEX LRV rules | The deadline and the color rule that keep the warranty alive | The paint date on the schedule; the LRV of the color |
| Expansion | AZEK 1/8 inch per 18 feet; VERSATEX 60 to 70 degree install, three-board rule | How much a long PVC run moves and how to stop it | Glue in every joint, fasteners to the schedule, a mild day for the fascia |
| MDF limit | Woodgrain species guide | Where MDF cannot go | PVC (V) on the same profile for wet rooms; nothing MDF outside |
A line with a number, two fractions, and a letter is a spec. "Colonial casing, primed" is a description. Ask for the sheet.
"Lifetime" has a list of words. Here is AZEK's.
AZEK's Trim and Moulding Lifetime Limited Warranty is two pages, and the whole thing turns on one sentence. For the lifetime of the product, AZEK warrants it free from manufacturing defects that result in corrosion, rotting, splitting, splintering, delamination, warping, or swelling excessively from moisture. That is the covered list. It is a good list, and it is exactly the list of things wood trim does.
Then the exclusions, and three of them matter on a real house. Paint. The warranty does not cover painted finishes or coatings applied by the purchaser or anyone else, and says failing to follow the painting guidelines may void it. Weathering. Fading, chalking, and darkening from sun and weather are defined as ordinary and are not covered. Heat. Damage from extreme heat sources, including sunlight reflected off Low-E glass, is out. Add improper installation, wrong fasteners, and water intrusion into the wall, and you have the same shape of exclusion list every siding warranty has.
The remedy is the part to read twice. If the claim is valid, AZEK will repair or replace the trim or refund the portion of the purchase price paid for it, at its option, and the warranty says in so many words that it does not cover removal, installation of the replacement, labor, or freight. You have 90 days from finding the defect to file, with proof of purchase and a photo, and AZEK gets to inspect before anything comes off the wall. It transfers once, to the next owner, and only if the sale happens within five years of the original purchase.
So "lifetime" on PVC trim means this: the board will not rot, split, or swell for as long as you own the house, and if it does, you get a board. The paint, the labor, and the fade are yours. That is not a knock. It is what the sheet says, and it is still the longest trim warranty on our shelf.
For comparison, in the makers' own words: VERSATEX says lifetime, fully transferable, non-prorated. LP's trim and fascia ride on the SmartSide 50-year warranty, with labor and material paid through year 5 and material only after that, prorated 2.22 percent a year, one transfer. TruExterior publishes a 20-year limited warranty on its trim; read it for the schedule. The interior sticks, MDF and finger-joint and solid, come with the maker's statement that they are what the sheet says they are, and not much else, which is why the 3-day rule and the glue in the miter matter more than any paper.
| Read for | Where it hides | What a strong answer looks like |
|---|---|---|
| The covered list | The statement of warranty, first paragraph | Rot, split, splinter, delaminate, warp, swell: the things wood does, in writing |
| Paint | The exclusions, usually its own sentence | You know the paint is on you, and the painter knows the LRV rule |
| Weathering | A definition of "ordinary" weathering | You expect the white to chalk a little and did not buy the warranty for that |
| The remedy | The "what the manufacturer will do" paragraph | Repair, replace, or refund the board; labor and freight are named as not covered |
| Notice window | The claims section | Somebody knows it is 90 days and nobody pulls the board first |
| Transfer | Its own paragraph near the end | Once, and you know whether there is a time limit on the sale |
| The paint window | On primed product, the install guide and the exclusions | The date is on the schedule: 150 or 180 days, by maker |
| Installation | The first exclusion, always | Fasteners, glue, and gaps match the maker's guide, and the crew has read it |
What is on the covered list. Is paint excluded, and what is the color rule. Who pays labor on a replacement. How many days to file. Does it transfer, and is there a clock on that. If it is primed, what is the paint deadline and whose calendar is it on.
Before You Price Trim
Know what you are finishing with.
Three short reads on trim and moulding. Written for the builder who has to answer to the money, and for the eye that sees it every day.
Frequently Asked
Trim specs and warranties, answered.
What does a lifetime warranty on PVC trim actually cover?
Does a trim warranty transfer when I sell the house?
How much does PVC trim expand, and does it matter when it is installed?
What moisture content should interior trim be?
Can MDF trim be used in a bathroom or on the exterior?
What are the exterior ratings on trim?
Come See It
Put your hands on it first.
Specs only tell you so much. Come walk the yard and the showroom.
119 Cumberland St, Ashland City. The coffee’s on.