Today, while people's expectations from textile materials are increasing, the comfort features expected in casual clothes are also increasing. Some important parameters in terms of comfort are protection against wind and rain conditions; protection from the cold; passage of body vapor through layers of clothing; providing the necessary freedom of movement of the garment, etc. The aim of the project is the thermal comfort feature that includes a chemical and membrane layer in a multi-layered structure; is to produce breathable (water vapor permeable) and water-repellent denim fabric and to determine the optimum production method. In this context, optimization studies were conducted by applying membrane and chemicals to the denim fabric. Water vapor resistance, air permeability, capillary wetting, thermal resistance, thermal conductivity, thermal absorbance, and bond strength tests were applied to the product created within the scope of this project. In the experiments, better results were obtained in the air permeability and water vapor resistance parameters of the 10 g/m², polyurethane membrane laminated water-repellent silicone coated sample compared to the other membranes. It was observed that the percent of vertical capillary wetting in the rigid fabric was higher than the membrane laminated, and water repellant applied samples. When different membranes were evaluated, there was no enormous difference between thermal resistance, thermal conductivity, and thermal absorbance values, but the best values of separation bond strength were observed in the sample with 10 g/m² polyurethane membrane and silicon water-repellent outer coating.