There is gap of varying width (from 3cm to 8cm) and depth 100cm, between two constructed wall. The gap was supposed to have expansion joint material (Elastomeric). The bottom of the gap is also supposed to have water proof material. Can anybody advice how to fill this gap and which material shall be suitable?

Hello Mahmood,
The material that can be used between 2 walls must be any joint expansion fillers includes low viscosity epoxy resins, silicone gels, and cork and woods such as southern yellow pine, redwood, or western cedar.

Epoxy and silicone sealants also offer excellent moisture, dirt, and plant exclusion protection.

Most liquid or gel sealants are self-leveling to ensure a flat, blemish-free finish and may be painted or colored to match the rest of the structure.