Is the window leaking air and making a buzzing sound in winter? Apply sealant to the gaps of doors and windows like this to keep warm and quiet!

The gaps between the door and window frames and the walls are the main channels for heat loss (cold in winter and hot in summer), noise transmission, and rainwater leakage. Using the right sealant and applying it correctly can significantly improve the insulation, sound insulation, waterproofing and airtightness of doors and windows, making your home more comfortable and energy-saving.

Core skills: choose a sealant with good elasticity, distinguish between inside and outside, fill fully, and pay attention to nodes

Choose a sealant with high elasticity and good weather resistance:

Displacement capacity is the core: Doors and windows are affected by temperature changes, wind pressure, and switch vibration, and the gaps will expand and contract. You must choose a sealant with a high displacement capacity level (≥±25%, preferably ±35% or higher). Silicone glue (neutral) and high-quality MS glue are the first choice, with good long-term elastic recovery rate and not easy to crack.

Excellent weather resistance: Exposed to the outdoor side, it needs to withstand ultraviolet rays, wind and rain, and high and low temperature cycles. Silicone glue has the best weather resistance, and MS glue is also excellent. Avoid using acrylic glue (easy to age and crack outdoors).

Neutral and non-corrosive: Avoid acidic glue from corroding window frames (especially metal frames) or walls.

Distinguish between indoor and outdoor, and choose the right type:

Outdoor side: The primary task is waterproof, weather-resistant, and UV-resistant. Neutral silicone glue (general-purpose or weather-resistant special type) is the most reliable and common choice. MS glue is also an excellent alternative.

Indoor side: The main function is airtightness and beauty, and some occasions need to be painted.

If you need to paint it later: choose a paintable sealant, such as polyurethane glue (PU) or paintable MS glue. Pay attention to confirm its compatibility with interior wall paint.

If you don’t need to paint: neutral silicone glue or MS glue is enough, beautiful and durable.

Inside the kitchen and bathroom doors and windows: Anti-mildew silicone glue or MS glue is preferred.

Construction key points:

Clean and dry: Thoroughly remove dust, oil stains, old glue residues, and loose objects in the gaps to ensure clean and dry. The gaps in old walls may need to be deeply cleaned with a brush or a hair dryer.

Backing material (when the gap is >10mm deep or >25mm wide): Use a closed-cell polyethylene (PE) foam stick to fill the gap deep. Function: 1. Control the thickness of the glue (glue thickness ≈ half the width of the gap, and not more than 12mm); 2. Save glue; 3. Provide three-sided bonding to facilitate stress release; 4. Prevent the glue from sagging (reverse seam, top seam).

Full and continuous filling: Apply sealant continuously and fully along the gap to ensure that the gap is completely filled and fully contacted with the window frame and both sides of the wall. Avoid glue breakage, bubbles or holes. The cross-section of the glue strip should be slightly convex (concave after trimming).

Key processing nodes: The four corners of the window frame are stress concentration and easy leakage points. Ensure that the glue strips transition continuously here without breakpoints. The inner and outer glue strips should be closed at the edge of the window frame.

Perfect finishing: Timely trimming and shaping, compacting the edges, forming a smooth transition surface (usually trimmed into a concave shape), which is conducive to drainage and beauty.

Curing protection: Avoid rain and pollution during curing (especially on the outside). After complete curing, subsequent operations (such as installing window covers) can be carried out.

💡 Key points: Outdoor waterproofing relies on silicone (or high-quality MS), and indoor painting chooses PU/MS. The gap is deep and wide, and the backing is filled and repaired in place. The corner nodes are the focus. Elastic weather resistance is the life of door and window seam sealant!