How to fix a mirror to a wall without drilling
You can fix a mirror to a sound wall without drilling by bonding it with a neutral-cure mirror adhesive, applied in vertical strips on the back of the mirror, then holding the mirror in place with tape or a temporary support while it cures for at least 24 hours. Do not use ordinary acetic (vinegar-smelling) silicone: it attacks the mirror backing and causes black spots that spread in from the edges. Very large or heavy mirrors should still get a bottom support as well as the adhesive.
Why ordinary silicone ruins mirrors
The silver layer on a mirror is protected by a thin paint backing. General-purpose acetic silicone releases acetic acid while it cures, and that acid can get through the backing to the silver. The result shows up weeks or months later as dark patches, usually starting at the edges.
Manufacturers say this plainly. Akfix's data sheet for its 100E universal silicone says it must not be used on mirrors because of its acidic cure, and Henkel says the same about Pattex SL212. Both are good products for tile and sanitary joints, just not for this job.
Which adhesive to use
Neutral mirror adhesive: Akfix 900N
Akfix 900N Neutral Mirror Adhesive is a neutral, oxime-cure silicone made for bonding mirrors. Akfix publishes it for mirror walls in shops, restaurants and gyms, and for bonding mirrors to sound plaster, concrete, wood, doors and ceramic wall tiles. Its data sheet lists:
- Skin formation in 5 to 10 minutes at 23 °C and 50% humidity
- Cure rate of at least 2.5 mm per day under the same conditions
- Movement capability of plus or minus 25%, so it can take some flexing of the wall
- Application temperature of +5 °C to +40 °C
- A 310 ml cartridge, transparent
The data sheet also lists Şişecam certification to TS EN 1036-1, the European standard for silvered mirror glass. One restriction to note: Akfix says not to use 900N if the mirror is backed with a plastic safety film. Peel a corner of the backing or ask the glass supplier if you are not sure.
Polymer construction adhesive: Pattex PL 200
Pattex PL 200 is a silane-curing polymer adhesive, isocyanate-free and solvent-free, that Henkel publishes for glass and mirror fixing and cites against DIN EN 1036-1. It bridges gaps up to 20 mm, which helps on walls that are not flat, and can be applied on damp surfaces. It is sold in cartons of 12 by 380 ml.
High-tack montage adhesive: Akfix MS High Tack
Akfix MS High Tack is a polymer adhesive with a strong initial grab, made for bonding heavy building materials without clamps. Akfix lists mirrors and glass among its substrates. It is white, so it must not show at the edges of the mirror.
For most bathroom, bedroom and wardrobe mirrors, a dedicated mirror adhesive such as 900N is the straightforward choice.
Step by step
1. Check the wall
The bond is only as strong as the surface it sticks to. The wall should be clean, dry, dust-free and grease-free. Akfix's data sheet says to remove loose material and repair unsound plaster, and that dusty or porous surfaces may need priming. If you are bonding onto paint, the mirror is effectively hanging from the paint film, so scrape off anything flaking. Ceramic tile is a good surface; clean it with spirit first to remove soap film.
2. Clean the back of the mirror
Akfix recommends cleaning the painted back of the mirror with methylated spirit. Let it dry.
3. Apply the adhesive in vertical strips
This is the step most people get wrong. Akfix's instructions for 900N are:
- Apply in vertical strips 3 to 5 mm thick and 10 to 30 cm long, depending on the length of the mirror.
- Leave about 3 to 7 cm between strips.
- Do not apply in a circle or a closed rectangle around the edge. That traps air behind the mirror, and over time it can damage the backing.
- If you are fitting several mirrors side by side, leave at least 1 to 2 cm between them for air circulation.
Keep the strips a few centimetres in from the edges so that adhesive does not squeeze out and show.
4. Place the mirror within 5 to 10 minutes
Akfix says the mirror has to be bonded to the wall within 5 to 10 minutes of applying the adhesive, before a skin forms. Set the bottom edge on spacers or a straight timber batten, then press the mirror firmly onto the wall.
5. Hold it while it cures
Akfix advises fixing the mirror with tape or a similar support to stop it sliding down, with the tape running vertically rather than horizontally. For anything bigger than a small bathroom mirror, a temporary batten or wedges underneath is wise.
6. Leave it at least 24 hours
Akfix gives at least 24 hours for full cure, depending on bead thickness, humidity and temperature. Do not remove the support early, and avoid slamming a door that a mirror is bonded to during that time. Fresh adhesive can be cleaned off with solvent; once cured it can only be removed mechanically.
When you should still add a mechanical support
Adhesive alone is fine for most domestic mirrors on a sound wall. Add a bottom support channel or clips as well when the mirror is very large, when it is over a basin or bed where a fall would be dangerous, when it is fixed to a door, or when the wall surface is old paint you cannot test. That does mean drilling a few small holes, but the adhesive still does most of the work and keeps the glass in one piece if it cracks. Akfix's own description of 900N makes that point: a bonded mirror is safer because there is less risk of large pieces of glass falling if it breaks.
Common mistakes
- Using acetic silicone because it was already in the toolbox.
- Running a bead all the way round the edge of the mirror.
- Bonding onto flaking paint, dust or a wet wall.
- Taking the tape off the next morning on a cold, dry day. Moisture-curing adhesives cure more slowly in cool, dry conditions.
- Bonding a mirror that has a plastic safety film on the back with a product that is not approved for it.
Where to buy
Akfix 900N is on our adhesives page alongside the other montage adhesives. Glass and aluminium shops buying by the carton can request a trade quote on our trade page. Collect from our Nairobi trade counter at Royal Business Park, opposite Complast, Old Mombasa Road (Monday to Saturday, 8:00 to 17:30), or order for delivery at KSh 350 flat countrywide, free over KSh 15,000. If you want a second opinion on your wall or mirror size, send a photo on WhatsApp.
Common questions
How many cartridges of mirror adhesive do I need?
Akfix gives a yield of about 10 metres of bead per cartridge for a strip 10 mm wide and 3 mm thick. A mirror of 60 × 90 cm with five strips of 25 cm uses about 1.25 metres of bead, so one cartridge does several mirrors.
Can I stick a mirror onto tiles?
Yes. Akfix lists ceramic wall tiles as a suitable surface for 900N. Clean the tiles with spirit first and leave the grout lines alone.
Can I use double-sided mirror tape instead?
Tape can work for small, light mirrors on smooth surfaces. For anything larger, or in a humid bathroom, a mirror adhesive gives a more reliable bond. Tape is still useful for holding the mirror while the adhesive cures.
How do I remove a mirror stuck with adhesive?
Cured mirror adhesive has to be cut through, usually with a wire or a long blade worked behind the glass. Wear gloves and eye protection and expect the mirror may crack.