ᐅ Which screws and wall anchors do I need for challenging wall types when installing IKEA BESTA units?

Hello everyone,

I am currently planning to mount an IKEA Besta shelving unit on a wall that is somewhat challenging to assess – specifically, it is an older wall with a combination of old plaster on brickwork, which is rough in some areas and crumbly in others. Additionally, there are sections with exposed concrete where I also want to hang the unit.

My question is: which screws and wall plugs are most suitable for these difficult wall types to ensure a secure and long-lasting attachment?

I want to avoid any risks, as the shelving unit will be quite heavy and improper fixing could cause damage. Does anyone have experience or recommendations on which types of wall anchors (e.g., heavy-duty anchors, expansion anchors, chemical anchors) and screw sizes work best for this kind of wall?

I am also interested in the appropriate drill bit size for the chosen anchors and screws to avoid causing a weak point in the wall.

Thanks in advance for your answers!

The challenge with older walls made of mixed materials is primarily to match the type of anchor to the specific wall section.

- For brick masonry with a relatively solid substrate, classic nylon anchors or expansion anchors are suitable. Screws should have at least a 6 mm diameter, with 6x60 mm or 8x60 mm being common sizes for BESTA shelves.

- For crumbling plaster areas, I recommend chemical anchors. The liquid injection fills cavities and creates a reliable fixing.

- Concrete areas can be anchored with heavy-duty anchors or traditional concrete anchors. The screw size should be matched to the load and the anchor.

It is important that the drill bit size exactly matches the anchor size. Too large a hole reduces the holding strength, while too small prevents the anchor from gripping properly.

A tip: With mixed walls, different anchors may be necessary for different areas – carefully test the wall’s strength on site.

I will go into more detail on the issue, since you have several wall types in one project.

First: Mechanical anchoring on older walls with plaster on brick must be planned very carefully, as each method has specific requirements.

- Brick walls:
Classic nylon anchors of size 8 mm, combined with suitable screws ranging from 6x60 to 8x80, are recommended here. Drill cleanly with a masonry bit (matching the anchor size) and thoroughly clean the hole to ensure the anchor grips well.

- Crumbling plaster:
Chemical anchors (injection mortar including glass fiber reinforcement) are the preferred solution. The procedure:
1. Drill a hole about 8–10 mm (approximately 0.3–0.4 inches), depending on the anchoring system
2. Blow out dust or clean with a brush
3. Inject the mortar
4. Insert the glass fiber reinforcement and let it cure
5. Use a screw with the correct length and diameter

This type of anchoring supports significantly higher loads, even with poor substrate quality.

- Exposed concrete:
Heavy-duty anchors or bolt anchors are suitable for concrete. These are usually hammered in and secured with a screw. Important: Use the correct anchor size, typically 10–12 mm (approximately 0.4–0.5 inches) in diameter, depending on the load.

If the shelf is very heavy (over 50 kg or 110 lbs load), I would always recommend a combination of chemical anchors (for weak spots) and heavy-duty anchors (for concrete areas).

Question: How long will the shelf be, and will it be loaded along its entire length? This significantly affects the distribution of the fastening points.

Domau0 schrieb:
If the shelf is very heavy (over 50 kg (110 lbs) load), I would always recommend a combination of chemical anchors (for weak spots) and heavy-duty anchors (for concrete areas).

The shelf will be about 2.4 meters (7 ft 10 in) wide and depending on the design with doors and compartments, I should expect at least 30-40 kg (66-88 lbs) distributed over four fixing points. I plan to mount the shelf centrally across several wall sections, so having safety margins in the fixing is important to me.

Are there significant differences when choosing chemical anchors, or brands that are particularly reliable for DIY use? I want to avoid the mortar becoming brittle over time or moisture weakening the anchoring.

Regarding the drill bit: Should I use a special drill bit set for chemical anchors, or is a standard masonry bit sufficient? What common mistakes during drilling should I definitely avoid?

I would appreciate tips on the exact steps and procedures – including how long the mortar needs to cure before I can start loading the shelf.

I’m happy to give you a brief guide on how to properly use chemical anchors to securely mount your IKEA BESTA on challenging walls.

1. Drill Bit Selection:
- For chemical anchors, always use a standard SDS-Plus masonry drill bit that exactly matches the anchor size (usually 8 or 10 mm (0.3 or 0.4 inches)).
- Do not use a hammer drill in hammer mode; only a drill with a percussion function without hammering is allowed.

2. Preparing the Drill Hole:
- Immediately after drilling, remove the dust from the hole using a vacuum cleaner or compressed air (if available).
- Blow out the hole at least twice to remove as much dust as possible.

3. Applying the Mortar:
- Pull the cartridge a bit at the start to mix the mortar thoroughly.
- Fill the mortar into the hole from the inside out, avoiding air bubbles.

4. Inserting the Anchor:
- Slowly screw in a fiberglass anchor or threaded rod, do not twist and push at the same time.

5. Curing Time:
- Depending on the product, the mortar needs between 30 minutes and up to 24 hours to cure; ideally 8–12 hours.

6. Installing the Screws:
- Finally, use screws of the recommended length (usually at least 6–8 cm (2.4–3.1 inches)).

The biggest mistake is not cleaning the hole thoroughly and not allowing the mortar to fully cure. This leads to poor adhesion and potential failure of the fixing.

Using this method, you will achieve a durable, load-bearing anchoring even in brittle plaster or uneven substrates.