When you need solid, long-lasting support for level surfaces, pressure treated wood shims offer durability and resistance to moisture and pests. This guide highlights five strong, reliable options that perform well in wet or outdoor environments, making them ideal for decks, doors, windows, and furniture adjustments. Ideal buyers include DIY homeowners tackling damp or yard-side projects, contractors working on exterior framing, and anyone needing rot-resistant leveling wedges.
- Nelson Wood Shims: Composite Shims & Wedges for Leveling – Waterproof (24 Pack) 8-Inch
- Stock Your Home: Composite Shims (36 Pack) – Never Rot for Leveling
- Glazelock: Prescored Wood Shims for Leveling (12 Shims) 8-Inch
- PHYXOLOGY SUPPLY: Pro-Grade Composite Shims for Heavy Duty Leveling – 24 pk
- WOBBLE WEDGES: Original Wobble Wedge Flexible Plastic Shims, 30 Pack
Composite Shims & Wedges for Leveling – Waterproof (24 Pack)
Best for moisture-prone interiors and exteriors, this 24-pack combines wood fiber with plastic to deliver durable, waterproof shims. They snap cleanly, with dual-sided score lines to help you cut to size quickly. Ideal for toilets, windows, and cabinet leveling in kitchens, bathrooms, basements, and decks where water exposure is likely. Limitation: while highly moisture resistant, they may not provide the same wood grain aesthetics as solid wood shims in finished woodworking projects.
Composite Shims (36 Pack) – Never Rot
Best for projects that demand heavy-duty, rot-resistant performance, these 36 pre-scored composite shims are designed to hold up under outdoor weather and wet indoor conditions. They offer 37 pre-scored lines, enabling rapid snaps to the needed size without extra cutting. Suitable for leveling heavy appliances, tables, and outdoor fixtures. Caution: heavier loads may require multiple shims to spread weight evenly.
Pro-Grade Composite Shims for Heavy Duty Leveling
Best for high-load applications, these 7.75-inch shims are made from recycled materials and claim greater load support than wood. They are designed for both indoor and outdoor leveling—useful for cabinets, countertops, doors, and deck components. A caution: the product emphasizes heavy-duty versatility; ensure you have a stable plan for distributing load across shims to avoid point-load stress on any single shim.
Glazelock Prescored Wood Shims for Leveling
Best for precise, quick installations, these prescored 8-inch wood shims eliminate manual cutting, saving time on door and window alignment. They feature tapered edges for easier insertion and are kiln-dried for consistent performance. They are suitable for professional and DIY use in interior remodeling. Limitation: being wood, they may be more susceptible to moisture than composite options in very damp environments.
Mobile Home Hardwood Shims
Best for mobile homes and RV settings, these hardwood shims measure 4″ x 9″ x 1″ and come in a 30-pack. They offer traditional solid-wood performance with straightforward installation. Use them where builders expect wood-leveling components rather than composite wedges. Caution: hardwood shims may be less resistant to prolonged moisture than composite/shim blends.
The Original Wobble Wedge
Best for universal home use, these flexible plastic shims stabilize uneven furniture and fixtures, including toilets and shelving. They are simple to trim to the needed size and are designed to protect floors from scratches. Limitation: not designed for heavy-duty outdoor leveling; best for indoor, everyday adjustments where moisture is minimal.
Buying Guide
- What material suits my environment? If you face high humidity, rain exposure, or termite concerns, opt for rot-proof composites or pressure-treated blends rather than pure wood.
- How much load will the shims bear? For heavy furniture, appliances, or decking, choose thicker, reinforced or multi-shim setups that spread weight rather than relying on a single shim.
- Do I need prescored or pre-cut shims? Prescored or snap-notched shims speed up installation and reduce on-site waste, especially for DIY projects.
- What size and length work best? Common lengths are 8 inches or longer; ensure the shim thickness and taper align with the gap you’re filling.
- Are moisture and soil contact factors important? For exterior applications, look for water-resistant or waterproof options and consider termite-resistant materials.
- Will I require trimming? Some shims are designed to be trimmed for exact fit; others are pre-cut and ready to snap to size, saving time.
Quick Comparison Table
| Product | Best For | Material | Notable Feature |
|---|---|---|---|
| Composite Shims & Wedges – 24 Pack | Bathrooms, decks, damp areas | Composite (wood fiber + plastic) | Waterproof, dual-score lines |
| Composite Shims (36 Pack) – Never Rot | Outdoor and heavy-duty leveling | Composite | 37 notches, rot-proof |
| Glazelock Prescored Wood Shims | Door/windows alignment | Wood | Prescored, tapered edges |
| Pro-Grade Composite Shims | Appliances, cabinets, DIY | Composite | 30% heavier load capacity |
| The Original Wobble Wedge | Indoor furniture and fixtures | Plastic | Flexible, easy trimming |
Frequently Asked Questions
- Do pressure treated shims exist? Yes. Many shims marketed for damp or outdoor use feature rot-resistant composites or treated wood blends to resist moisture and pests.
- Can I use wood shims for exterior leveling? Yes, but consider moisture exposure. Composite or treated wood options offer longer lifespans in wet environments.
- How do I choose the right thickness? Start with the gap measurement; if you need fine adjustments, prefer shims with pre-scored lines for precise snapping and size control.
- Are prescored shims better than raw wood shims? Often yes for speed and consistency, especially in DIY projects with multiple leveling points.
- Can I use these for toilet installation? Yes, several damp-resistant shims are suitable for toilet level adjustments, but verify weight and load distribution.
- Do these shims require sealing or finishing? For visible installations, you may finish with trim or paint; otherwise, shims can remain hidden behind cabinetry or fixtures.