Stair tread bolt Set 5A, for mortar anchoring in brick and concrete

Stair tread bolt Set 5A – almost invisible groove fixing

LamiFIX stair tread bolt Set 5A fixes grooved treads to the wall at the sides. The connector is recessed into the tread groove and remains largely hidden. This discreet connection lets the stair design take centre stage.

Installation version A is particularly popular with architects because very little of the fixing remains visible. Each tread can be removed individually, making replacement or later work on the stairs easier.

Application and design

Set 5A is designed for mortar anchoring in brick and concrete walls. This version has no acoustic isolation. Version A is suitable for straight stairs or in combination with a tread suspension system. Versions B or C are intended for winding stairs.

Accurate drilling for a precise fit

Our drill bushes guide the drill bit accurately in angle and position throughout the drilling depth. Predrill at Ø16 mm with light hammer action, then finish at Ø20 mm without hammer action to avoid breaking the internal webs of the brick. Tip: rebar drill bits are particularly suitable for drilling brick without hammer action.

For accurate drill guidance, we lend matching drill bushes free of charge for up to three months. Installation using drill bushes is shown in the LamiFIX catalogue on page 26 . Matching drill bits are available separately.

Version C as an economical alternative

For particularly quick and economical installation, choose stair tread bolt Set 5C . In version C, the tread rests on the support; no groove or hole in the tread is required.

Installation tip: fit treads from top to bottom

This keeps the fixing screws underneath the treads accessible.
Clean the holes and insert the mesh sleeves. Then install each tread individually:

1. Fill the mesh sleeve with mortar from back to front: 1/9 cartridge per Set.
2. Insert the anchor with a twisting motion to distribute the mortar around it.
3. The easiest method is to fit the wooden tread or a temporary tread immediately and screw it to the anchor while the mortar is still workable.

At 20 °C, our mortar provides approximately two minutes more working time than a high-speed mortar – enough to install one tread.

Required quantity per Set

• 1 type A/B stair anchor, T=78 mm, M10, LF 3623.102.1, zinc-plated steel with INOX Decor cover sleeve
• 1 LamiFIX M10 connector, LF 35.M10x30 (catalogue LF 1035.130)
• 1 raised countersunk screw 5.5 × 32 mm, LF 1541.002.1
• 1 mesh sleeve Ø20 × 85 mm, LF 1710.020.1
• 1 wall rosette, LF 1801.025.1
• 1/9 cartridge of anchoring mortar LF 1720.002.1
• 1/5 adjustment washer LF 3605.002.1 for an 18–24 mm gap; each whole washer includes 1 long cover sleeve LF 3601.001.1 (26 mm)
• 1/100 threadlocker LF 3806.243.1

Ordering and sales units

The component list shows the quantities required per Set. Screws are supplied in packs of 100, mortar in whole cartridges and threadlocker in whole tubes; adjustment washers are sold individually. The basket rounds quantities up to whole sales units and shows the total price for the number of Sets ordered.

Article number: LF 3623.105.4. Standard version, Set length T=88 mm.