To seal the hairline gap between your wall and your neighbor's wall for waterproofing, you can follow these steps:
Clean the area: Start by thoroughly cleaning the gap between the walls. Remove any dirt, dust, or debris using a brush, vacuum, or damp cloth. It's important to have a clean surface for the sealant to adhere properly.
Choose a suitable sealant: Select a high-quality, waterproof sealant that is appropriate for the materials of your walls. Silicone-based sealants are commonly used for this purpose as they provide excellent waterproofing properties and flexibility to accommodate any slight movements between the walls. Ensure the sealant is compatible with the wall surfaces and is designed for interior or exterior use as needed.
Prepare the sealant: Follow the manufacturer's instructions to prepare the sealant. This usually involves cutting the tip of the cartridge and inserting it into a caulking gun. Ensure the caulking gun is in good working condition.
Apply the sealant: Apply a thin, even bead of sealant along the hairline gap between the walls. Start at one end and slowly move along the entire length of the gap. Use steady pressure on the caulking gun to control the flow of the sealant. Try to fill the entire gap while avoiding excess build-up.
Smooth the sealant: After applying the sealant, use a caulk smoothing tool, a damp finger, or a small spatula to smooth and shape the sealant. This will create a neat and professional finish. Remove any excess sealant or smudges from the surrounding surfaces using a damp cloth or sponge.
Allow for drying and curing: Give the sealant sufficient time to dry and cure according to the manufacturer's instructions. This can typically take several hours to a few days, depending on the product and environmental conditions. Avoid disturbing or touching the sealant until it has fully cured.
Monitor and maintain: Periodically inspect the sealed area to ensure the sealant remains intact and performs its waterproofing function effectively. If you notice any signs of damage or deterioration, reapply the sealant as necessary.
It's worth noting that if the gap between the walls is particularly large or there are structural issues, it may be best to consult a professional contractor or a waterproofing specialist to assess the situation and provide appropriate solutions.