Concealed screw connection comparison

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Concealed screw connection for wooden decking

There are various systems for the concealed screwing of wooden terraces. But which one is best and what are the different pros and cons? Our comparison gives you an overview.

Screwing from below or lateral attachment?

The systems for the concealed fastening of wooden terraces can be sorted into two types of construction. Some systems rely on the decking board being screwed on from below, while others work with the board being fastened at the side. Both solutions offer different advantages and disadvantages. All in all, however, we have had better experiences with screwing from below, which is why we recommend this solution to our customers.

screwing from below

✓ Decking can work

✓ low risk of splintering

✓ secure hold

✓ good ventilation of the terrace

✓ suitable for every plank profile

x relatively complex installation

Side attachment

x Decking should not work

x increased risk of splinters due to milling

x high risk of default

x Poor drying of the lateral groove

x Lateral grooving of the planks necessary

✓ Relatively easy assembly

Fastening systems in detail

BioMaderas Clips

System: Screw connection from below
Material: stainless steel
Demand per crossing TD/UK: 2 clips
Need screws per TD/UK: 5 screws
Price per sqm*: 18 €
assembly height: 6mm
Width: 27mm
Length: 54mm
plank width: every plank width possible
Disassembly: min. 5mm joint
Wood preservation: very good
Types of wood: any decking wood
Peculiarity: also available in black

Summary: The technically best system for concealed fastening of wooden terraces. However, it is also more complex than some other solutions.

Early Bohlenhalter

Early Bohlenhalter

System: Screw connection from below
Material: galvanized steel
Demand per intersection TD/UK: 1 bar
Need screws per TD/UK: 3 screws
Price per sqm*: 12 €
assembly height: 5mm
Width: 25mm
Length: 190mm
plank width: 95 to 150mm
Disassembly: not possible
Wood preservation: Well
Types of wood: any decking wood
Peculiarity: the classic

Summary: Relatively inexpensive system, which, however, requires more space on the substructure and is not available in stainless steel.

Hedgehog V2

Hedgehog V2

System: lateral attachment
Material: stainless steel
Demand per intersection TD/UK: 1 connector
Need screws per TD/UK: 2 screws
Price per sqm*: 20 €
assembly height: n / a
Width: n / a
Length: n / a
plank width: any width
Disassembly: not possible
Wood preservation: Well
Types of wood: any decking wood
Peculiarity: Board tends to splinter

Summary: Expensive since an extra lever tool is required for around €300. Technically critical because the mandrel is pushed in laterally without pre-drilling.

Terracon Clippers

System: Screw connection from below
Material: Plastic
Demand per intersection TD/UK: 1 clipper
Need screws per TD/UK: 3 screws
Price per sqm*: 18 €
assembly height: 15mm
Width: n / a
Length: n / a
plank width: 120mm to 150mm
Disassembly: not possible
Wood preservation: very good
Types of wood: no hardwood
Peculiarity: Joint spacing is specified

Summary: Similar to the early plank holder with a continuous bar. Unfortunately made of plastic and not suitable for hardwood. The system with the highest installation height.

Sihga plank fix

Sihga plank fix

System: Screw connection from below
Material: stainless steel
Demand per crossing TD/UK: 2 PlankFix
Need screws per TD/UK: 5 screws
Price per sqm*: 23 €
assembly height: 5mm
Width: 20mm
Length: 61mm
plank width: any plank width
Disassembly: min. 8mm joint
Wood preservation: very good
Types of wood: any decking wood
Peculiarity: the BioMaderas clip similar

Summary: To the BioMaderas Clip almost identical in construction and technically a very good solution. Small drawback: the price and the larger gap for disassembly.

Instant wood clamp connector

Instant wood clamp connector

System: lateral attachment
Material: stainless steel
Demand per intersection TD/UK: 1 connector
Need screws per TD/UK: 1 screw
Price per sqm*: 13 €
assembly height: 0mm
Width: n / a
Length: n / a
plank width: any plank width
Disassembly: min. 6mm joint
Wood preservation: moderate
Types of wood: any decking wood with a groove
Peculiarity: In-house development of instant wood

Summary: Clever solution, since assembly is quick and inexpensive. Unfortunately at the expense of structural wood protection, since poor ventilation and floorboards with grooves are necessary.

* Prices for 120mm board width and 5mm joint, as of December 2020.

Concealed screw connection

starting from 31,95 

starting from 24,95 

3,95