Lynden Door Standard Construction Series

Lynden Door’s Standard Construction Series divides cleanly along core material lines — hollow core models (H8, H4) for basic interior passage doors and particle board models (P8, P4, P20) when sound control or fire ratings matter. The weight difference tells the story: H8 doors at 32 pounds for a 36x80 slab versus solid-core alternatives that weigh substantially more.

Core Construction Drives Performance

The H8 model represents the entry point — hollow core construction at 1-3/8” thickness yields about 1.6 pounds per square foot. That’s light enough for easy handling during installation but sturdy enough for residential and light commercial applications. The bonded sanded core assembly provides dimensional stability without the weight penalty of solid cores.

P8, P4, and P20 models switch to particleboard cores for applications where hollow doors fall short. The P8 maintains the same 1-3/8” thickness as the H8 but delivers solid-core feel and better sound attenuation. Step up to P4 for 1-3/4” thickness, or choose P20 when building codes demand a 20-minute fire rating.

Face material options span the quality spectrum. MDF and hardboard faces handle paint well for budget installations. HDF (high-density fiberboard) adds durability. Wood veneer brings natural grain patterns, while laminate (HPDL) stands up to high-traffic commercial environments.

Dimensional Standards and Actual Measurements

Standard widths run 24”, 28”, 30”, 32”, and 36” — but here’s what matters for installation: actual slab width runs 0.19 inches less than nominal. That 36” door actually measures 35.81”. The gap allows for proper clearance and hardware operation.

Model	Core Type	Thickness	Fire Rating	Primary Use
H8	Hollow	1-3/8”	Non-rated	Basic interior passage
H4	Hollow	1-3/4”	Non-rated	Sturdier interior passage
P8	Particleboard	1-3/8”	Non-rated	Sound control applications
P4	Particleboard	1-3/4”	Non-rated	Enhanced sound control
P20	Particleboard	1-3/4”	20-minute	Code-required fire separation

All models require acclimatization to jobsite conditions before installation — standard practice but worth emphasizing in Montana’s dry climate. Store flat on level surfaces in temperature-controlled environments.

Environmental Compliance and Warranty Coverage

CARB Phase II and TSCA Title VI compliance comes standard across the line. EPD (Environmental Product Declaration) documentation available for LEED projects. FSC certification available company-wide for chain-of-custody requirements.

The 1-Year Limited Warranty covers manufacturing defects in materials and workmanship for interior use. Standard coverage for this product category — nothing exceptional but adequate for quality doors installed properly.

Frequently Asked Questions

What’s the real difference between H8 and P8 doors? Core material changes everything. H8 hollow cores work fine for closets and bedrooms where sound transmission doesn’t matter. P8 particleboard cores add mass for better sound deadening between rooms — worth it for home offices or media rooms.

Can these doors be trimmed to fit? The design includes wider top and bottom rails specifically for on-site trimming. Standard practice allows minor adjustments without compromising structural integrity.

Which face material holds up best in rental properties? Laminate (HPDL) faces resist damage better than any other option. MDF and hardboard work fine for owner-occupied homes but show wear faster under tenant abuse. Wood veneer looks best but requires more maintenance.

Do H4 doors justify the extra thickness over H8? The 1-3/4” H4 provides a thicker, sturdier feel than the 1-3/8” H8 — noticeable when closing. For main floor applications where guests interact with doors, the upgrade makes sense. For upstairs bedrooms, H8 suffices.

When is P20 fire-rated required? House-to-garage entries always need 20-minute ratings. Some jurisdictions require fire-rated doors between attached dwelling units or in certain commercial applications. Check local codes — requirements vary by location and occupancy type.