FAQ
TL;DR: For foam‑block walls, 8×65 or 10×80 are the longest common options, and "fi6 is completely sufficient" for screw strength. Use dedicated anchors, space several fixings per rail, and place them near cabinet hangers. [Elektroda, Anonymous, post #19536050]
Why it matters: This FAQ gives DIYers clear sizes, anchor types, and placement tips to hang heavy kitchen cabinets safely on block walls.
Quick Facts
- Identify the wall first (aerated concrete, silicate, hollow brick), then pick the matching dowel/anchor. [Elektroda, PawełS1717, #19530666]
- For aerated concrete, dia 8 mm screws with AAC‑dedicated plugs work; two screws can hold one full cabinet. [Elektroda, palmus, post #19535819]
- For incomplete silicate/hollow, use chemical anchors with mesh sleeves or Fischer Duopower 8×65/10×80. [Elektroda, Anonymous, post #19536050]
- Use several fixings per rail; if the rail lacks holes, drill more. 10×120 is a robust pick. [Elektroda, PawełS1717, #19533507]
- Place fixings close to cabinet hangers to improve load paths and reduce bending. [Elektroda, rafbid, post #19533883]
What screws and anchors should I use for foam block (aerated concrete) kitchen cabinets?
Use dowels dedicated to aerated concrete and pair them with 8 mm screws. That combination is sufficient for typical wall cabinets. A cabinet full of porcelain can hang on a strip with two screws. If multiple cabinets share a rail, add one or two more screws. The wall’s AAC strength still matters, so avoid short or generic plugs. Keep spacing even and avoid edge distances that crumble AAC. [Elektroda, palmus, post #19535819]
Are 6×80 mm screws enough for a cabinet rail on a block wall?
For screw strength, fi6 is sufficient, but anchor length in your wall is critical. Choose the longest system length available for your anchor type. In the Duopower family, 8×65 or 10×80 are the longest sizes. If your rail slots limit screw diameter, adjust the rail holes rather than shortening anchors. As the expert said, “fi6 is completely sufficient,” provided the embedment is maximized. [Elektroda, Anonymous, post #19536050]
When should I step up to 10×120 mm fixings?
Use 10×120 when you need deeper bite in softer blocks or thicker finishes. It increases embedment and safety margin under heavy, loaded cabinets. Install several pins across one rail. If the factory rail lacks enough holes, drill more holes to expand the anchor pattern. This improves load sharing and reduces the chance of pull‑out. [Elektroda, PawełS1717, #19533507]
Should I use “quick‑assembly” frame fixings in a slotted cabinet rail?
Avoid relying on quick‑assembly frame fixings for slotted rails. They often clamp only via the sleeve’s flange and may not match slot diameters. As one pro warned, “The screw itself DOES NOT HOLD in such a dowel!” Use anchors compatible with the wall and rail holes instead. That reduces the risk of a slip or sudden failure. [Elektroda, balonika3, post #19530747]
Do I need washers under the screw heads?
Usually no. Focus on correct hole sizing and anchor selection so the screw head bears properly on the rail. If your dowel requires fi10 screws and the rail holes are tight, enlarge the rail to 11–12 mm for clearance. That eliminates the need to ‘patch’ fit with washers and maintains proper clamping. [Elektroda, Anonymous, post #19536050]
How many anchors per suspension rail do I need?
Use several anchors along each rail to distribute loads from heavy cabinets and contents. If the rail has too few factory holes, drill more to expand the pattern. Spacing anchors regularly reduces point loads and improves safety. Bigger anchors do not replace the need for a good pattern. [Elektroda, PawełS1717, #19533507]
Where exactly should I place the anchors along the rail?
Place fixings as close as practical to the cabinet hangers. This aligns the load path and reduces bending in the rail and wall face. It also minimizes rail flex during door operation and uneven loading. Fill remaining spans with evenly spaced anchors. [Elektroda, rafbid, post #19533883]
What if my wall is hollow brick or incomplete silicate?
Use chemical anchors with mesh sleeves for incomplete silicate or fragile, voided substrates. Alternatively, consider universal plugs like Fischer Duopower in lengths 8×65 or 10×80. Prioritize maximum usable length and proper hole sizing in the rail. Choose one system and follow its drilling and torque instructions precisely. [Elektroda, Anonymous, post #19536050]
My rail holes are 10 mm—should I enlarge them?
Yes, if you use fi10 dowels/screws, give yourself clearance for drilling tolerances. Enlarge rail holes to 11–12 mm to avoid misalignment fights. This helps keep anchors long and straight rather than compromising embedment to fit tight slots. Deburr the holes after drilling to protect finishes. [Elektroda, Anonymous, post #19536050]
How do I mount a cabinet rail on aerated concrete (AAC)?
- Level and mark the rail. Plan several fixings across its length.
- Drill the rail and wall; add extra rail holes if the factory pattern is sparse.
- Install long anchors and tighten to spec; recheck level before hanging cabinets. [Elektroda, PawełS1717, #19533507]
Are 8 mm screws really enough for heavy, porcelain‑filled cabinets?
Yes, when paired with AAC‑dedicated plugs and installed correctly. “A cabinet full of porcelain will hang easily on a strip with 2 screws.” For multiple cabinets sharing one rail, add one or two screws to keep loads balanced. This keeps pull‑out and shear within safe limits for quality AAC. [Elektroda, palmus, post #19535819]
Does wall type really change the anchor choice?
Absolutely. Identify whether it’s reinforced concrete, aerated concrete, silicate, or hollow brick. Then match the dowel or anchor system to that substrate. This choice dictates drill size, embedment, and load capacity. Guessing the wall can lead to the wrong anchor and poor holding power. [Elektroda, PawełS1717, #19530666]
Is chemical anchoring better than standard plugs here?
Use chemical anchors when the substrate is weak or voided and expansion plugs cannot grip reliably. In solid, suitable block with correct plugs, mechanical anchors are simpler and effective. Select based on wall type first, then on load and embedment needs. [Elektroda, cysiekw, post #19530610]
Any common mistakes or edge cases to avoid?
Avoid quick‑assembly frame fixings in slotted rails; they can hold only by the sleeve’s flange. That can slip under load because the screw alone does not grip the wall. Choose anchors designed for your substrate and rail geometry to prevent this edge‑case failure. [Elektroda, balonika3, post #19530747]
