Root-proof and waterproof construction method for planted roof
A. Classification of roof gardens

1. Greening of concrete roof (heavy roof garden)
2. Light steel and wooden roof green (light roof garden)

B. Problems to be considered in roof gardens and their solutions
1. The problems that need to be solved for planting roof waterproofing
1) Prevent water seepage;
2) Prevent plant roots from piercing the waterproof layer and penetrating the building;
2. Solution
For heavy-duty roof gardens, the waterproof planting roof adopts a double-layer waterproof system. The first layer is an ordinary waterproof layer, which can effectively solve the problem of water leakage; the second layer is a root-resistant waterproof layer for planting, which has chemical resistance. The role of roots can effectively solve the problem of plant roots piercing the waterproof layer.
For light roof gardens, due to the light weight of the planting system as a whole, polymer waterproofing membranes with physical root blocking properties can be used to solve the problems of waterproofing and plant root puncture.

C. The construction of the roof garden should pay special attention to two points
One is load-bearing, and the other is waterproof. The two points are not sloppy. The roof garden should be built on the top surface of the building structure that fully meets the national building structure and the roof load meets the safety completion acceptance standards.
1. Investigate the load. The net load of constructing garden-style roof green buildings should not be less than 300 kg per square meter.
2. Construction safety treatment.
(1) In order to ensure the roof waterproof, drainage and fire protection requirements, the planting surface of plants should not be directly close to the edge of the building facade, and should be isolated by 20-50 cm gravel belt or light material belt.
(2) The drains, drainage observation holes, ventilation holes, etc. of the roof greening should be separated by a 10 cm gravel belt or a light material belt.
3. Test the existing waterproof ability of the roof and do a closed water test. If it leaks, make a waterproof layer first. The safety protection layer that effectively prevents water seepage generally includes flexible waterproof, rigid waterproof and coated waterproof layer.
4. Place the barrier root membrane. In order to prevent plant roots from penetrating the waterproof layer, a special root barrier should be set on the waterproof layer to avoid damage to the building structure.
5. Pave a moisturizing blanket to maintain moisture in the nutrient matrix.
6. Pave storage and drainage aeration panels to improve the aeration of plant roots and substrate.
7. Place a filter membrane to prevent synthetic matrix particles from losing with water. The filter layer is directly laid on the storage and drainage vent plate. When laying, the effective width of the lap joint shall not be less than 10 cm, and extend to the side wall of the building, and the folded height shall not be less than 20 cm.
8. Lay a lightweight synthetic nutrient substrate. It is necessary to choose a light artificial planting substrate that has the advantages of safe and reliable physical and chemical indicators such as storage and drainage, fertilizer retention, ventilation and insulation, and expansion coefficient, and a pH value of 6.8 to 7.5.
9. Reasonable installation of irrigation system, drip irrigation and sprinkler irrigation should be selected. Water immediately after planting, and it is not advisable to go too often afterwards, because the plants will grow too fast due to the large water and reduce the overall resistance.
10. Necessary plant fixation technology.