Application of Spray Foam Insulation Equipment in Waterproof and Insulation Integration of Slope Roof

    Traditional roofing insulation materials mostly use extruded polystyrene board. Roof waterproofing materials are mostly made of coil waterproofing. However, in the case of sloping roofs with exposed exposed steel heads, the above two methods have great drawbacks. The roofing structural panels are reserved. The steel head will cause damage to the insulation board and the waterproof membrane, and the damage is difficult to repair because the steel head is protruding, and each patch is a weak link of waterproofing and heat preservation; the extruded polystyrene board will also be highlighted during the paving process. The damaged steel head is damaged, causing holes and bubbles to cause environmental pollution. The gap between the polystyrene boards will also become a cold bridge, which will affect the insulation effect.

As a waterproof and thermal insulation integrated material, the use of Spray Foam Insulation equipment to spray hard foam polyurethane on-site overcomes the disadvantages of traditional materials, such as non-insulation, non-waterproof, non-waterproof, waterproof layer, and leakage of insulation layer. Compared with other single waterproof or thermal insulation materials, rigid foam polyurethane has obvious advantages: rigid foam polyurethane has a multi-purpose function, and has many functions such as waterproof, heat preservation and sound insulation. It has excellent thermal insulation performance and is the smallest thermal conductivity in domestic building materials. One of the thermal insulation materials with the highest thermal resistance has ideal water impermeability. The Spray Foam Insulation equipment is used in the on-site spraying method to achieve continuous and seamless seaming of the waterproof and thermal insulation layer, and the waterproof and impermeability are excellent.

Combined with our application in practical engineering, we will introduce the application of rigid foam polyurethane waterproof and thermal insulation integrated materials in the waterproof insulation design of slope roof.

1 Project Overview

The first phase of the reconstruction and expansion of Xiyuan Hospital of Chinese Academy of Sciences is a hospital complex. It is used as a transitional outpatient building during the second phase of demolition. The project is located in the courtyard of Xiyuan Hospital, No. 1 Xiyuan Playground, Haidian District, Beijing. The comprehensive building is a frame shear wall structure, with 2 underground floors, 3 floors above ground, a height of 14m, a building area of 28,866 m2, and a sloped roof area of 2,100 m2. Because it is adjacent to Yuanmingyuan and the Summer Palace, it is required to design antique roofing. The Φ10 steel head is pre-buried on the slope roof to hang small blue tiles and glazed tiles. For details, refer to Atlas 08BJ1-1, 10-PU, and spray hard foam directly on the roof panel structure. Polyurethane, then glazed tile. Roof waterproofing grade I, designed for 25 years, slope roof waterproofing, thermal insulation design spray 55mm thick type III rigid foam polyurethane waterproof insulation integrated material, no other waterproof layer (according to Atlas 08BJ1-1, P404 line 3, adopted High-pressure Spray Foam Insulation equipment on-site spraying insulation and waterproof integrated rigid foam polyurethane can be added without waterproof layer).

2 Hard foam polyurethane waterproof insulation integrated material introduction

2.1 Development history of rigid foam polyurethane

Polyurethane rigid foam insulation material for construction industry is an important branch of polyurethane industry. It is characterized by multi-purpose, and has the functions of heat preservation and waterproof. These products have been used for 40 years in the European construction industry since the 1960s. The production process is relatively mature and the durability is up to 30 years. Some countries have also passed legislation to use polyurethane as a thermal insulation material for the construction industry. In recent years, with the rapid development of China's building energy-saving market, rigid foam polyurethane insulation products have been widely used in the field of building insulation and waterproofing, and have become one of the leading energy-saving products in the market.

At present, the application of rigid foam polyurethane waterproof and thermal insulation integrated materials in the domestic construction industry is still in the initial stage. Fortunately, in order to speed up the innovation of building insulation materials and promote the promotion and application of rigid foam polyurethane in the field of building energy conservation, the Science Department of the Ministry of Construction has specially established the “Polyurethane Building Energy Saving Application Promotion Working Group” to promote the rigid foam polyurethane insulation and waterproof materials. The application of domestic building energy-saving industry.

2.2 Hard foam polyurethane has good thermal insulation and fire resistance

Hard foam polyurethane (referred to as PU rigid foam) is an additive such as a polyether polyol (abbreviated as A material) and an isocyanate (referred to as B material) with an appropriate amount of foam and a curing agent, and the closed cell ratio is not lower than that after chemical reaction. 95% polyurethane rigid foam polymer, thermal conductivity ≤ 0.224W / (m · K), only half of the thermal conductivity of EPS foamed polystyrene board, energy saving effect is very good. Spraying a thickness of 40mm can meet the national requirements of 65% energy saving. Material density ≥ 55Kg / m3, compression performance ≥ 300kPa, dimensional stability (70 ° C, 48h) ≤ 1%, water absorption ≤ 1%, impervious to water. After adding a certain proportion of flame retardant, the hard foam polyurethane material has good fireproof performance, and its own combustion performance can reach B1 grade. It belongs to thermosetting insulation material. It does not melt in case of fire, and the surface forms dense carbonized layer, no burning drip, which is better. Fire resistance performance. The composite polyurethane board formed by the 20mm thick mortar protective layer on the surface of the rigid foam polyurethane is sent to the National Building Materials Testing Center for testing. According to the burning performance classification method of GB8624-2006, the burning performance level can reach A2 grade (non-homogeneous products). .

2.3 Hard foam polyurethane has excellent waterproof performance

The polyurethane rigid foam continuous dense skin and 95% high strength interconnected wall closed cells have ideal water impermeability. The Spray Foam Insulation equipment is used in the on-site spraying method to achieve continuous and seamless seaming of the waterproof and thermal insulation layer, forming a seamless roof insulation shell, which is excellent in waterproof and impermeability. According to the "hard foam polyurethane insulation waterproof engineering technical specifications" GB50404-2007 Appendix A hard foam polyurethane watertight test method, 0.2MPa, 30min impervious. Hard foam polyurethane is not brittle at low temperature -50 °C, does not flow at high temperature +150 °C, does not bond, can be used normally, the temperature range of anti-aging strength is large, better than general coil waterproof. According to Atlas 08BJ1-1, P366 line 11, spray thickness of not less than 40mm can be used as two waterproof layers. On-site spraying construction can well overcome the impact caused by protruding roof members such as steel bars. The situation before and after construction is shown in Figure 1 and Figure 2.

2.4 Hard foam polyurethane has high self-bonding strength

Commonly used in the construction of bonded traditional thermal insulation boards, there are common problems such as cracking, hollowing and easy falling off. However, rigid foam polyurethane is used to spray A and B materials through the on-site Spray Foam Insulation equipment to produce atomized spray to the dry and smooth crucible. On the surface of the base layer, the atomized liquid falls into the base layer and foams within 3 to 5 seconds. Because the liquid material has fluidity and permeability, it can enter the void of the roof base layer to foam, and the polyurethane rigid foam bond strength ≥ 100KPa, has excellent self-adhesive properties. It can penetrate into the gap of the main structure and be integrated with the base surface of the base layer when it is foamed by high-pressure spraying on the spot, and it can play the role of sealing the gap. It has strong resistance to wind, and its bond strength exceeds the tear strength of rigid foam polyurethane itself. Its crack resistance is good, delamination is not easy to occur, and roof water penetration along the layer gap is avoided.

2.5 Good environmental performance

It adopts fluorine-free foaming technology, which is non-toxic, non-polluting, non-irritating, mold-free, biologically parasitic, and has good environmental performance. In addition, it has a long service life, low maintenance, and the least amount of waste generated during the entire period from design, construction, renovation to reuse and final disposal, and is the most environmentally friendly waterproof insulation material from the whole life cycle.

2.6 Construction speed is fast

The rigid foam polyurethane is sprayed and molded on the spot using Spray Foam Insulation equipment. The process equipment is simple and easy to operate. It can be used in any complicated roof construction work and at the same time complete waterproof and heat insulation construction. The traditional practice is to separate the two processes. It is necessary to first construct the waterproof and protective layer and then lay the insulation layer or construct the insulation layer and the protective layer to construct the waterproof layer first. There is a technical interval between the processes, which leads to a long construction period; the waterproof coiled material is hot melted. A group of 3 people can work around 200m2 per day. Hard foam Spray Foam Insulation construction generally consists of a set of equipment for a group of 3 people. In sunny weather, each group can spray about 1000m2 per day, which is more than ten times better than laying traditional waterproof and thermal insulation materials (considering technical intermittent between processes).

2.7 Low construction cost

Spraying 55mm thick type III rigid foam polyurethane waterproof and heat insulation integrated material is equivalent to the traditional practice of two coils of waterproofing and one layer of extruded polystyrene board insulation. The cost of laying two sheets of waterproofing labor and materials is about 120 yuan. The price of flat rice for the manual and material of the paste-extruded polystyrene board is about 40 yuan (material and labor prices are based on the current cost information); while the labor cost of the hard foam polyurethane is about 140 yuan (hard foam polyurethane is new) Material, cost information can not find the reference price, the owner needs to be approved). Spraying rigid foam polyurethane construction not only has a fast construction speed, but also has low construction cost.

3 Construction preparation and construction points

3.1 Construction environmental conditions

The atmospheric temperature at the construction site should not be lower than 10°, and the relative temperature of the air should not be less than 85%. Otherwise, the quality of the project will be affected, the construction efficiency and curing time will be reduced; the wind should be less than 3, otherwise the polyurethane rigid foam will be everywhere under the wind. Flying, there is no guarantee that the surface of the polyurethane rigid foam coating will have a continuous uniform spray ripple. Construction on rainy or snowy days is strictly prohibited.

3.2 Major machinery and personnel preparation

The roof area of the slope is 6000m2, and the continuous spraying is completed within 3d. It is necessary to prepare 2 sets of Spray Foam Insulation equipment of Yabu Company, 4 feeding pumps, 2 spray guns and matching hoses. According to the operation of one set of equipment for three people, one project team manager, technical leader, material staff, quality inspector and safety officer are required, and 6 workers are required.

3.3 Grassroots cleaning

The surface of the base layer should be flat, firm and dry (water content <8%) and free of oil. The dust, sand, gravel, debris, oil and mortar protrusions on the base layer must be removed before construction.

3.4 Local detail processing

Only the exposed steel head of the slope roof needs to be treated separately. Because the steel head is easy to rust and is easily disturbed during the tiling process, it is necessary to apply a layer of polyurethane paint on the steel head and around the root, so that this part can be completely solved. Water seepage problem.

3.5 Spraying polyurethane

1) Test spraying: Check and debug the special Spray Foam Insulation equipment before Spray Foam Insulation, strictly control the mixing ratio of A material, B material and additives, and carry out test spraying to confirm that no problem is solved after spraying three 500mm×500mm×55mm test blocks. , the performance of the material is tested, and the construction is carried out after passing the test.

2) The first layer of spraying: spraying should start from the side of the roof structure, from far to near, the spraying angle should be maintained at 45 ° ~ 60 °, the distance of the spray gun from the working surface ≤ 500mm, the spray gun moving speed is even. The thickness of the first layer should be controlled at about 10mm. Within 20min after the spraying operation, it is strictly forbidden to walk or be pressed by the person to fully guarantee the foaming, stability and curing of the polyurethane.

3) Second layer spraying: The second layer should be applied after the first layer of rigid foam polyurethane is cured. The spraying construction is perpendicular to the first layer and fills the construction defects of the first layer of rigid foam polyurethane.

4) The construction methods of the 3rd, 4th and 5th floors are the same as above until the design thickness is reached.

5) Construction thickness control: Before the large-area construction, spray the same proportion of rigid foam polyurethane, make 55mm thick round cake as the construction thickness reference material, control the final construction thickness, the round cake can be completely integrated with the post-spray hard foam polyurethane. together. The round cake reference objects are arranged in a plum blossom shape with a spacing of 3 m, which can effectively control the construction thickness.

3.6 Cleaning Spray Foam Insulation equipment

After the spraying operation is completed, the feeding pump should be turned off first, the feeding should be stopped, and the materials remaining in the equipment should be cleaned with compressed air, and then the spray gun should be cleaned.

3.7 Protective layer construction

After the acceptance of the rigid foam polyurethane, a 20 mm thick polymer cement mortar protective layer was applied.

4 quality acceptance

4.1 Inspection batch division

According to the "Hard Bubble Polyurethane Thermal Insulation and Waterproof Engineering Technical Specification" GB50404-2007, every 500~1000m2 is divided into one inspection lot. Less than 500 m2 should also be divided into one inspection lot; each inspection lot should be checked every 100 m2, each place Must be no less than 10 m2. The detailed structure should be inspected in full.

4.2 Acceptance of main control projects

1) Hard foam polyurethane and its supporting materials must meet the design requirements. Inspection method: Check the factory certificate, quality inspection report and on-site re-inspection report.

2) There must be no leakage or water accumulation. Inspection method: water spray test.

3) The thickness of the rigid foam polyurethane must meet the design requirements. Inspection method: steel needle insertion and inspection.

4.3 Acceptance of general items

1) The rigid foam polyurethane should be firmly bonded to the base layer, and the surface should not be damaged, delaminated, drum, hole and crack. Inspection method: observation inspection.

2) Anti-cracking polymer cement mortar should be firmly bonded to rigid foam polyurethane, and there should be no empty drum, crack, sanding and so on. Inspection method: observation inspection.

3) The flatness of the hard foam polyurethane surface is 5mm. Inspection method: Check with 1m ruler and wedge feeler.

5 Safe and civilized construction and finished product protection measures

1) Install a 1200mm high steel pipe enclosure around the slope roof to prevent people from falling.

2) Operators should wear helmets and necessary protective tools as required.

3) It is forbidden to throw objects at high altitude to prevent high-altitude falling objects from hitting. When loading and unloading at high altitude, it must be bundled firmly.

4) Smoking is strictly prohibited on the construction site.

5) Construction workers are strictly forbidden to wear slippers and spike shoes, and flat-slip shoes should be worn.

6) Conscientiously achieve the “cleaning of the finished materials”, clean up the site in time, and protect the site clean and tidy. Waste should be concentrated and treated uniformly.

7) After the construction of the rigid foam polyurethane, it is strictly forbidden to make holes in the roof and add structures.

6 Conclusion

China's application of rigid foam polyurethane waterproof insulation integrated materials started late, only introduced technology and equipment from Germany in 1997, began to promote the application. However, in recent years, the state has increased the research and promotion of hard foam polyurethane, revised the "hard foam polyurethane insulation waterproof engineering technical specifications", and supported the development of enterprises in this field. The rigid foam polyurethane waterproof insulation integrated material has been localized. And reached the level of advanced foreign technology, reducing costs. The improvement of technology and the reduction of cost have laid a foundation for the large-scale promotion and application of rigid foam polyurethane waterproof insulation materials in China.

The rigid foam polyurethane waterproof and heat insulation integrated material not only has low construction cost, high construction speed, but also has great social benefits such as energy saving. According to relevant experts, by 2020, if urban buildings all meet energy-saving standards, they can save 335 million tons of standard coal per year; air-conditioning peak load can be reduced by 80 million kW, equivalent to China's new power capacity from 1988 to 2002. The sum of the electricity generated by the 4.5 or Three Gorges Dam, or equivalent to an annual investment of 1 trillion yuan in electricity construction.

Hard foam polyurethane can also be applied to flat roofs, but flat roof I grade waterproof needs to add a waterproof, and need to deal with the daughter wall, tube root and other nodes. The waterproofing and heat preservation of the exposed steel head parts are treated on the slope roof surface, and the application of the rigid foam polyurethane is more advantageous, and the effect cannot be achieved by other materials.

The comprehensive building has been put into use for more than a year. The roof waterproofing and heat preservation effect is good, and the rigid foam polyurethane waterproof and heat insulation integrated material has a large-scale promotion value. I hope that everyone can learn more about rigid foam polyurethane waterproof insulation integrated materials, and more and more projects will use this advanced waterproof insulation material.