ᐅ Drilled into the EIFS (Exterior Insulation and Finish System) facade and used standard anchors. Should it be sealed?

Hello.

We have a prefabricated house with a plaster facade and an external thermal insulation composite system. I recently attached a house number by drilling 6cm (2.4 inches) into the facade according to the instructions and using a standard wall plug (there was no insulation fixing included). Since this comes from one of the market leaders for house numbers, doorbells, and mailboxes, I assumed the instructions could be trusted without question.

The house number is mounted on threaded rods that are supposed to be inserted into the wall plugs. Unfortunately, when pushing them in, the plugs slipped further into the insulation, and now I can’t get them out. The house number itself can still be mounted.

However, I am concerned that the facade might absorb moisture or that a thermal bridge could form at this point because special insulation fixings weren’t used and the wall plugs have slid into the facade insulation.

The house number can be pulled out, but the plugs remain embedded in the facade.

I was thinking of sealing the hole completely with silicone and then reattaching the house number, but I wanted to ask the experts here for their opinion on whether that would be a good idea.

Thanks in advance for any advice!

Here are the details of the facade:

Plaster facade (U-value 0.14 W/m²K)
- Mineral lightweight plaster with a final coat
- 120 mm (4.7 inches) external thermal insulation composite system (ETICS, thermal conductivity 0.040 W/mK)
- Structural sheathing
- Timber frame construction
- 140 mm (5.5 inches) mineral insulation (thermal conductivity 0.035 W/mK) between timber studs
- Vapor retarder
- Installation layer (counter battens)
- Inner sheathing

Use a high-quality hybrid sealant, apply it into the holes, insert the house number, and enjoy the result.

KarstenausNRW schrieb:

Use a good hybrid sealant, apply it into the holes, insert the house number, and enjoy the result.

That sounds good, thank you for the reply!

Can you recommend a specific hybrid sealant?

I used Sikaflex-521 or 522 for a similar case; it is a UV- and weather-resistant, strong-adhesion sealant, 300 ml (10 fl oz), white.
P.S. The manufacturer’s instructions probably included something about the exterior wall material ;-)

i_b_n_a_n schrieb:

I used Sikaflex-521 or 522 for a similar case; it is a UV- and weather-resistant, strong-adhesion sealant, 300 ml (10 fl oz), white.
P.S. The manufacturer’s instructions probably mentioned something regarding the exterior wall material ;-)

Thank you for your tip; I’ll get that product then.

In fact, the manufacturer’s instructions didn’t say anything else about the exterior wall material; they only described this one procedure and didn’t include any insulation anchors.

Of course, that doesn’t mean I couldn’t or shouldn’t have looked into this topic more carefully beforehand. I’ve already been frustrated about that enough. But I’m glad that your answers have now offered a reasonable solution to resolve the issue 🙂

And in the future, please throw away the included wall plugs as your very first step after opening the packaging. The supplied plugs are generally only suitable, at best, for concrete and solid brick walls, which you will now find in a modern house mainly as the ground floor ceiling or in an exterior brick veneer wall.

But even if you happen to drill into a mortar joint in a solid brick wall, you can forget about using these plugs.

The manufacturer probably mentions somewhere in the instructions, more or less vaguely, that you should of course use appropriate fasteners. Otherwise, at least in the USA, you could sue them for a full renovation of your ETICS (external thermal insulation composite system) facade 😉