Marine board is now in stock at both our Ajah (Lekki) and Igando locations. Call or WhatsApp +2348082134079 to order alongside your rods and other materials.
Every contractor in Lagos knows the frustration. Your TMT rods arrive on site, your concrete is mixed and ready — and your shuttering boards are warped, water-logged or have already been used too many times to hold their shape. The slab finish suffers. The columns are uneven. The beams do not meet specification. The problem is not your concrete mix. It is your formwork material.
Marine board exists to solve this problem permanently. This guide explains exactly what marine board is, why serious construction professionals use it, and why Raloyd now stocks it alongside our full-gauge TMT rods so you can source your complete casting materials from one trusted supplier.
What Is Marine Board?
Marine board — also known as marine plywood or waterproof shuttering board — is a high-grade engineered wood panel manufactured specifically for environments where sustained contact with water or moisture is unavoidable. Unlike standard construction plywood, marine board is manufactured using waterproof adhesives throughout every layer and treated to resist moisture penetration even when in direct contact with fresh concrete.
The key difference between marine board and ordinary plywood is not just the surface coating — it is the internal bond. Ordinary plywood uses interior-grade glue that dissolves when it stays wet for extended periods. Marine board uses exterior-grade phenolic resin throughout, meaning every layer remains bonded even when saturated with moisture from fresh concrete. This makes marine board the correct material for construction formwork, shuttering and concrete casting applications.
When ordinary plywood contacts fresh concrete, the alkaline moisture from the concrete saturates the wood fibres and begins breaking down the internal glue layers. Within the curing period, standard plywood warps, delaminates and loses structural integrity. This compromises the shape of your cast element and can result in:
- Uneven slab soffit surfaces
- Out-of-plumb columns that require costly remediation
- Beam boxes that bulge under concrete pressure
- Boards that cannot be reused after a single pour
Where Marine Board Is Used in Lagos Construction
Suspended Slab Formwork
Suspended slabs — whether for residential first floors, commercial decking or high-rise floor plates — require flat, stable shuttering boards that can carry the full wet weight of concrete without deflecting. Marine board maintains its dimensional stability under load and produces smooth slab soffits that require minimal plaster finishing.
Column Formwork (Column Boxes)
Columns carry concentrated structural loads. The column box must maintain precise dimensions under the lateral pressure of poured concrete. Marine board's cross-laminated structure resists bowing and maintains the column's specified dimensions through the curing period, ensuring the finished column meets structural engineer specifications.
Beam Boxes
Beams — particularly at junction with columns — are subject to high lateral pressure during casting. Marine board provides the rigidity needed to maintain beam depth and width, directly affecting the structural performance of the finished concrete element.
Retaining Walls and Water Features
Any concrete work near water — retaining walls, swimming pool shells, water tanks, drainage structures — requires formwork that can withstand both the casting process and ongoing moisture exposure after striking. Marine board is the industry standard for these applications.
Staircase Formwork
Staircase soffit and riser shuttering requires boards that hold crisp edges and smooth surfaces. Marine board produces staircase finishes that require significantly less remedial plastering than ordinary plywood, reducing finishing costs directly.
Marine Board Sizes Available
| Thickness | Sheet Size | Common Use | Notes |
|---|---|---|---|
| 9mm | 4ft × 8ft (1.22m × 2.44m) | Light slab, stair risers, wall panels | Good for lighter loads |
| 12mm | 4ft × 8ft | Standard slab, beams, walls | Most commonly specified |
| 18mm | 4ft × 8ft | Heavy slabs, columns, high-load formwork | For high concrete pressure applications |
* Contact Raloyd on WhatsApp for current available thicknesses and pricing.
Marine Board vs Standard Plywood — The Cost Comparison
Many contractors choose standard plywood for formwork because the unit price per sheet is lower. This is a calculation that looks correct on paper but costs more in practice. Here is the real comparison across a typical 5-slab project:
| Factor | Standard Plywood | Marine Board |
|---|---|---|
| Reuses per board | 1–2 before warping | 6–8 with proper care |
| Boards needed for 5 slabs | 5 full sets | 1 set (used 5 times) |
| Surface finish quality | Poor to moderate | Excellent |
| Plaster remediation cost | High | Minimal |
| Total cost over 5 pours | Higher despite lower unit price | Lower total cost |
Raloyd now stocks marine board alongside full-gauge TMT rods, binding wire, BRC mesh, wire nails and quarter rod. You can now order your complete casting materials — rods and formwork — from one supplier, in one call, with one delivery to your site. No more separate trips to the iron market and the timber yard. No more delays waiting for two different suppliers.
How to Care for Marine Board Between Pours
- Strike carefully — Remove boards gently without prying against the face. Use release agents (form oil) before casting to ease removal.
- Clean immediately after striking — Remove all concrete residue before it hardens. A wire brush and water is sufficient.
- Store flat — Never store marine boards on edge unsupported. Lay flat on a level surface or stack horizontally with full support.
- Keep off the ground — Store on bearers to allow air circulation underneath. Direct ground contact accelerates edge degradation.
- Re-oil before every pour — A thin coat of shuttering oil on the face before each use significantly extends board life and improves concrete finish.
Order Marine Board From Raloyd Today
Available at both our Ajah (Lekki) and Igando locations. Send your required thickness, quantity and delivery location on WhatsApp for immediate pricing and availability.