Support Spacing
Confirm fastening intervals for board width, orientation, wind exposure and substrate.
THERMOStart your projectBUILDERS FIRSTSOURCE · ISSAQUAHGet a local Maximo consultation
Architectural Woodwork · Division 06 40 00 · Issaquah project guide
Thermo Ashfor Trim & Moulding.
Thermo Ash S4S boards provide crisp, sharp-edged architectural trim for fascia, corner details, window surrounds, and heavy-duty architectural transitions. Its resistance to cupping makes it ideal for wide board profiles up to 1x10.
APPLICATION SYSTEMThermo Ash · Trim & Moulding
1,320Janka Hardness
38.5Dry Density
Verify ProductDurability Rating
20 YearMaximo Warranty
Hardware & Nails
Exterior-grade stainless steel finish screws or trim fasteners approved for the profile.
Sub-framing Details
Solid blocking or furring backing with integrated flashing
Air Cavity Specs
Integrate back-ventilation behind wide fascia boards
Material & assembly planning
Key advantages &
installation rules.
Wide-Board Option
The cataloged 1x10 profile offers a broad hardwood face with reduced moisture response after thermal modification.
Clean Joinery
Sharp tools, dry material and correct fastening help maintain crisp miters and returns.
Assembly Guidelines for Trim & Moulding:
- Pre-drill screw holes when fastening near board ends and corners.
- Back-bevel bottom edges of exterior window and fascia trim to form a drip edge.
Reduced tangential movement supports more consistent joints through seasonal changes.
Thermal modification reduces moisture uptake and changes nutrients used by decay fungi; confirm the rating for the selected profile.
Real wood modified without added wood-preservative chemicals.
Consultation and order coordination through BFS Issaquah.
Cataloged Profiles
3 Profiles available for
Thermo Ash trim & moulding.
2x4S4S E4EHardwood strength and dimensional stability in a versatile structural-looking profile.Compare profile →
2x6S4S E4EA broad, solid profile with strong grain for decking, trim and architectural details.Compare profile →
1x10S4S E4EA wide hardwood trim board for fascia, frames and refined exterior transitions.Compare profile →Where to buy in Issaquah
Builders FirstSource Issaquah
Catalog available by consultation. Contact the Issaquah team to confirm availability, sample kits, and lead time for your selected Maximo profile.
Issaquah, WA 98029
(425) 391-8000
Monday–Friday, 7:00 AM–4:00 PMDealer information verified August 31, 2026. No in-stock claim is made on this site.
Request a local quote
Put this profile
on your project.
Tell us what you are building. Our team will review your wood selection and contact you to coordinate a Maximo consultation with Builders FirstSource Issaquah.
Frequently Asked Questions
Thermo Ash · Trim & Moulding
Can Thermo Ash trim boards be painted or solid-stained?+
Yes, but high-solids penetrating oils or semi-transparent stains are recommended to highlight the rich hardwood grain rather than hiding it under opaque paint.
Product and installation references