Sudden Valley Siding What LP SmartSide Actually Is
LP SmartSide is an engineered wood siding product made from wood strands bonded with resins, then coated with a treated finish meant to resist moisture and insects. It's lighter than fiber cement, easier on saw blades, and generally less expensive up front. A lot of contractors like it because it goes up fast and the material cost is friendly. We get asked about it often enough in Sudden Valley that we think homeowners deserve a straight answer about why we don't put it on houses here, rather than a vague brush-off.
What It Gets Right
To be fair to the product: modern engineered wood siding has come a long way from the OSB-based sidings of the 1990s that gave the category a bad reputation. LP's current SmartSide line uses a proprietary treatment process and a factory-applied primer or finish that does resist moisture better than older generations. It cuts easily, holds a screw or nail well, and can look quite good when it's fresh. For a builder working on a tight budget in a dry climate, it's not an unreasonable choice.
The problem is we don't build in a dry climate. Whatcom County sits right on the water, and Sudden Valley homes take on a steady diet of driving rain off Lake Whatcom combined with salt-tinged marine air moving in from the Sound. That combination is exactly the environment where wood-based products are put to the test the hardest, year after year.
The Trade-Offs That Concern Us
Our objection isn't that LP SmartSide is a bad product in general — it's that it's a wood product, and wood products have a fundamentally different relationship with moisture than fiber cement does. A few specific things drive our decision:
- Edge and end-cut vulnerability. Every cut edge on an engineered wood panel exposes the strand core. If it isn't sealed correctly during installation — every single time, on every single cut — that edge becomes the entry point for moisture. In a region with this much annual rainfall, that's a lot of edges that have to be perfect forever, not just on install day.
- Swelling and delamination risk. Once moisture does get past the finish, wood strand products can swell at seams and fastener points. It's not always visible right away, which means problems can develop behind the surface before a homeowner notices anything from the street.
- Moss and organic growth. Western Washington's long moss season isn't kind to any horizontal-lap siding, but a wood-based substrate gives moss, algae, and mildew more to hold onto and more to feed on than a cement-based product does. That means more frequent washing and more careful maintenance to keep the finish intact.
- Installation sensitivity. LP SmartSide's long-term performance depends heavily on correct field practices — sealing cut ends, proper caulking, flashing details, and keeping the bottom edge clear of standing water or soil contact. That's true of most siding to some degree, but the margin for error is narrower with an engineered wood product than with fiber cement.
- Warranty structure. LP's warranty is meaningful, but like most engineered wood warranties, it comes with maintenance obligations and installation requirements that, if not followed to the letter, can affect a claim. We'd rather stand behind a product with a straightforward, well-documented track record than manage that fine print on a homeowner's behalf.
Why We Standardized on James Hardie Instead
After years of doing exterior work in this climate, we made a call: we only install James Hardie fiber cement siding. It's not because we think every alternative is junk — it's because fiber cement is non-combustible, dimensionally stable, and simply doesn't have wood's relationship with moisture. There's no organic strand core to swell, delaminate, or feed moss growth. Hardie's ColorPlus factory finish is baked on and warrantied separately from the substrate, which means the color and the board are each backed on their own terms.
Hardie also builds region-specific HZ product lines engineered for different climate zones, which matters in a place like Sudden Valley where lake-effect moisture, coastal air, and heavy winter rain all show up on the same house. Combined with a strong transferable warranty, it's the product we're comfortable putting our name behind after the crew leaves.
What This Means for Your Home
If you already have LP SmartSide on your home, this isn't an alarm — it's a heads-up to stay on top of caulking, keep gutters and grade drainage working properly, and have any cracked or swollen boards addressed before moisture works further in. If you're planning new siding or a replacement project in Sudden Valley or elsewhere in Whatcom County, we'd rather tell you upfront why we passed on this category of product than sell you something we wouldn't want maintaining our own home through a Northwest winter.
| Factor | LP SmartSide | James Hardie Fiber Cement |
|---|---|---|
| Core material | Wood strand, resin-bonded | Cement, sand, cellulose fiber |
| Moisture response | Can swell/delaminate if breached | Non-organic, doesn't rot or swell |
| Combustibility | Wood-based | Non-combustible |
| Finish warranty | Tied to substrate terms | ColorPlus finish warranted separately |
If you'd like an honest opinion on your specific home — whether that's a repair, a partial re-side, or a full replacement — we're happy to come take a look. The estimate is free, there's no pressure, and we'll tell you what we'd actually do if it were our own house.