If you sell timber buildings or plan to, understanding the difference between solid log and glulam (glued laminated timber) construction is not optional — it determines your product range, your target market, and your profit margins. This comparison covers the technical, commercial, and practical differences that matter for builders, dealers, and distributors.
What Is Solid Log Construction?
Solid log construction uses single-piece timber logs — typically Nordic spruce — milled to a uniform profile with tongue-and-groove or interlocking joints. Wall thicknesses typically range from 28 mm for garden sheds up to 70 mm for insulated garden buildings and seasonal cabins.
The logs are precision-cut by CNC machinery and shipped as a flat-pack kit. Assembly is straightforward: logs stack vertically on a prepared base, interlock at the corners, and are secured with threaded rods or bolts. A competent team can assemble a standard garden cabin in one to three days.
Solid log is best suited for: garden buildings, summer houses, seasonal cabins, sheds, workshops, garages, and recreational buildings where full insulation to residential standards is not required. At 44–70 mm thickness, solid log walls provide reasonable thermal performance for three-season use, but they fall short of the insulation values required for year-round habitation under current building regulations in most European countries.
What Is Glulam Construction?
Glulam — glued laminated timber — is an engineered wood product made by bonding multiple layers of timber together under pressure with structural adhesive. The grain direction of adjacent layers is aligned (unlike cross-laminated timber, or CLT, where layers alternate), producing a structural member that is stronger, straighter, and more dimensionally stable than any single piece of timber of equivalent size.
Glulam wall logs for cabin and house construction are available in thicknesses from 88 mm up to 220 mm or beyond. At these thicknesses, the wall itself provides substantial thermal mass and, when combined with insulated cavity systems (twin skin construction), achieves insulation values that meet or exceed residential building regulations across Europe.
Glulam is best suited for: residential houses, permanent homes, high-specification holiday homes, commercial buildings, granny annexes, and any structure that needs to comply with building regulations for habitation. Glulam is also the standard choice for large-span structures where solid timber cannot provide adequate structural performance.
Technical Comparison
Structural Performance
Solid log construction relies on the natural properties of the timber species. Nordic spruce has a bending strength of approximately 24 N/mm² and a modulus of elasticity around 11,000 N/mm². These values are adequate for single-storey garden buildings and low-load structures, but they become limiting factors in larger buildings, longer spans, or multi-storey construction.
Glulam achieves significantly higher and more consistent structural properties because the lamination process eliminates the weak points found in natural timber — knots, grain irregularities, and moisture variations. Standard GL24h glulam has a characteristic bending strength of 24 N/mm² (the same nominal value as solid timber, but with far greater consistency and reliability) while higher grades such as GL28h and GL32h achieve 28–32 N/mm². More importantly, glulam members can be manufactured in sizes that are physically impossible with solid timber: beams of 500 mm depth and 12+ metre length are standard production items.
For dealers and builders, the practical implication is clear: solid log is limited to simple, single-storey structures with modest spans. Glulam unlocks the full range of architectural possibilities — large open-plan living spaces, two-storey buildings, vaulted ceilings, and structures that must carry significant roof loads (particularly important in snow-load regions).
Dimensional Stability and Settling
All timber moves with changes in moisture content. Solid log walls settle (compress vertically) as the wood dries after construction. Typical settling in a solid log wall is 3–5 percent of the wall height — meaning a 2.5 m wall may drop 75–125 mm over the first one to two years. This requires careful detailing around windows, doors, and internal partitions, and it limits the ability to fix rigid internal finishes immediately after construction.
Glulam is manufactured from kiln-dried laminations bonded at controlled moisture content (typically 12 percent plus or minus 2 percent). Settling in glulam walls is minimal — less than 1 percent — and is predictable. This means windows and doors can be fitted tightly from day one, internal finishes can be installed immediately, and there are no settling gaps to manage over time.
For dealers selling to end customers who expect a “move-in ready” building, glulam eliminates the single most common source of post-delivery complaints in log construction.
Thermal Performance
The thermal conductivity of spruce timber is approximately 0.13 W/mK. This means a 70 mm solid log wall has a U-value of approximately 1.4 W/m²K — adequate for a garden building but nowhere near the 0.15–0.20 W/m²K required by current residential building regulations in the UK, Germany, or Scandinavia.
A 180 mm glulam wall achieves a U-value of approximately 0.7 W/m²K from the timber alone. When combined with a twin-skin (double wall) construction incorporating a 100–150 mm insulation cavity, the assembly achieves U-values of 0.15–0.20 W/m²K — fully compliant with the most demanding energy efficiency standards.
For the dealer’s product strategy, this means solid log products serve the garden building and seasonal use market, while glulam products open the door to the residential market, holiday park developments, and any application where building regulations apply.
Durability and Longevity
Both solid log and glulam structures are highly durable when properly treated and maintained. Nordic spruce has natural resistance to decay, and factory-applied treatments extend the service life further. Well-maintained log buildings routinely last 50–100+ years.
Glulam has an additional durability advantage: the lamination adhesive (typically melamine or resorcinol-based, rated to EN 301 for structural bonding) creates a moisture barrier between each layer. Even if surface moisture penetrates the outer lamination, it does not propagate through the full wall section. This makes glulam more resistant to the gradual moisture-related degradation that can affect solid log walls in exposed locations.
Cost
Glulam is more expensive than solid log — typically 30–50 percent higher on a per-cubic-metre basis, reflecting the additional manufacturing steps (drying, planing, bonding, pressing, and re-profiling). However, this premium is partially offset by reduced construction time (minimal settling adjustments), lower maintenance requirements, and the ability to command higher retail prices in the residential market.
For dealers and builders, the margin calculation is what matters. A 44 mm solid log garden cabin might cost EUR3,000 from the manufacturer and sell for EUR6,000–EUR8,000. A 135 mm glulam residential cabin might cost EUR25,000 from the manufacturer and sell for EUR50,000–EUR75,000. The absolute margin on a single glulam project can exceed the margin on ten garden cabins — with a fraction of the customer management overhead.
Which Should You Sell?
The answer depends on your market positioning and business strategy.
If you are targeting volume — garden buildings, sheds, summer houses — solid log construction at 28–70 mm is your core product. The market is competitive, but volume is high and the product is relatively straightforward to sell and deliver.
If you are targeting value — residential homes, permanent annexes, holiday park developments, high-specification garden offices — glulam construction is essential. The products are higher ticket, the customers are more demanding, and the technical requirements are greater, but the margins and revenue per project are substantially higher.
The strongest position is to offer both. A dealer who can supply a 28 mm garden shed and a 220 mm glulam family home from the same manufacturing partner has the widest addressable market and the highest lifetime customer value. The end customer who starts with a garden office today may need a granny annexe in three years and a holiday cabin in five.
Finding a Manufacturer Who Covers Both
Most European log cabin manufacturers specialise in one end of the spectrum. The largest Estonian and Lithuanian factories (Palmako, Lasita Maja, Tene Kaubandus) focus on the garden building segment with wall thicknesses up to 70–92 mm. Finnish manufacturers like Honka specialise in the premium residential glulam segment but do not produce garden buildings.
The ideal manufacturing partner for a dealer who wants to offer the full range — from entry-level garden sheds to permanent residential homes — is one with production capability spanning both solid log and glulam construction, with wall thicknesses from 28 mm to 220 mm+. This kind of integrated capability is rare, but it exists among a small number of manufacturers who have invested in both traditional log milling and engineered timber production lines.
For builders and dealers evaluating their options, the key question is not “solid log or glulam?” — it is “does my manufacturing partner give me the flexibility to serve every customer who walks through the door?” Discuss your project requirements with a manufacturing partner who covers the full range.
Frequently Asked Questions
What is the cost difference between glulam and solid log construction?
Glulam typically commands a higher material cost per cubic metre due to the additional manufacturing steps involved: kiln drying, lamella grading, adhesive bonding, and hydraulic pressing. However, the total project cost difference narrows when accounting for reduced settling allowances, fewer maintenance interventions, and potentially thinner wall sections achieving equivalent structural performance. Dealers should present lifecycle cost comparisons rather than material cost alone.
Which construction method offers better airtightness?
Glulam construction achieves superior airtightness due to the dimensional stability of laminated timber. Solid log walls are subject to settling and shrinkage as residual moisture equalises, which can create gaps at joints and around openings. Glulam walls, manufactured from timber dried to 10-12% moisture content and bonded under pressure, exhibit minimal post-installation movement. For projects targeting low energy performance standards, glulam is the preferred specification.
Is solid log construction suitable for large residential buildings?
Solid log construction can be used for large residential buildings, but engineering considerations increase with scale. Buildings exceeding approximately 80 square metres of floor area or with wall heights above 3 metres require careful structural analysis for settling management, lateral stability, and load distribution. Glulam construction is generally recommended for larger residential projects due to its predictable structural behaviour and compatibility with building regulations for permanent dwellings.
