Erker - Where is the ceiling of the concrete slab sealed?

Hello everyone,

I bought a house, it is now 11 years old. There is a bay window attached to the house and on the ceiling of the bay window is the balcony, which is tiled. Some of the tiles are damaged and now my question is: can someone tell me where the concrete slab ceiling of the bay window is sealed? Or rather, how is a bay window constructed? Can I simply remove the damaged tile and replace it with a new one, or is there a seal under the tile? My concern is that the bay window does not become leaky. I hope you understand what I mean. Thank you, I ask for an explanation as I am not very familiar with this.

Hello spale,

the ceiling slab of the bay window is either sealed beneath the thermal insulation (assuming the ceiling slab of the bay window was insulated at the time), or there is a flat roof sealing on the concrete slab (or on the insulation), or it was sealed directly beneath the tiles, more precisely, beneath the tile mortar.

The sealing itself can consist of bitumen sealing membranes (flat roof sealing) or a so-called liquid membrane under the tile mortar (applied thick liquid sealing, whereby additionally the mortar and the grouting consist of sealing-modified cement). Furthermore, there can be a balcony system sealing, consisting of a sealing layer, separating layer, and/or drainage board including modified mortars.

Loose tiles can be replaced without risk; however, if tiles have to be forcibly removed to be replaced, there is a risk of damaging the sealing or the system build-up – since one neither knows where the sealing is located nor the system construction, unfortunately, I cannot provide any advice on the procedure.

Perhaps you can locate the planner/architect (listed on the plans) and ask him about the construction of the bay window ceiling.