天台防水
天台防水
Plan A
傳統PLAN A 天台防水的作法是打拆連重做防水層，包括新造三角線，凹坑、PU防水層、防水英泥沙及科水地台，重鋪飾面。
It is a very possible scenario that a building whose roof water insulation is not done thoroughly leaks water when it rains and snows. Water seeps into the building through holes and dents on the roof and damages the building.
Roof insulation should be done by experts using the right materials. Concrete should be made waterproof with roof waterproofing products, the coating should be applied, the edges of the coating should be beveled, drainage systems should be installed to prevent the formation of water puddles, and the process should be finished with a suitable paint or coating material as the top layer.
天台防水 參考案例
Plan A
天台防水
Plan B
PLAN B 天台防水的作法是修復飾面及於牆腳設置三角線，以Polyurea噴塗為防水層主體，噴塗到牆身高度，所有天台防水工程我們都會進行48小時注水測試，以及全方位紅外線檢測，確保防水層完整有效，並附上施工報告及十年保養。
- Compatibility with the existing roof surface: Pay attention to the type of material of the existing coating on your single-ply roof to avoid costly damage. For example, applying urethane over acrylic elastomeric could cause re-emulsification. Any surface with silicone on top would obstruct the adhesion of the waterproofing membrane.
- Resistance to sunlight damage: Unless you have trees above your building, the waterproofing membrane needs to be ultraviolet (UV) stable or resistant. Otherwise, it’ll lose its strength as the sun beats down on it.
參考案例
Plan B
拆解天台漏水的 7大原因
1.天台掃口有缺失及罅隙。
2.天面受熱，導致形成表面裂縫。
3.外牆滲漏引致。
4.地基沉降不均，導致樓板出現裂縫。
5.地台內部鋼筋生鏽，令混凝土等物料爆裂。
6.天台防水層防水物料質素欠佳或老化。
7.隔熱板有空隙，導致長期浸泡防水層。
8.測試方法: 目測及個案分析、水樣本分析、色水測試、噴灑水測試、微波濕度掃描、檢測雨量。
修復天台防水方案
| 重造天台防水層（打拆起底）
天台防水層老化或防水物料質素欠佳，不能提供良好防水功能，導致天台大範圍漏水。需專業的建商去判斷地磚有沒有空鼓、磚縫有沒有破損、天面地台有沒有粉化、防水層有沒有損壞等狀況。再決定如何重造天台防水。
- Chemical stability: The membrane should withstand chemicals from nearby industrial areas and fallen debris. If the membrane isn’t chemically inert, it could break down in the presence of soil and building materials.
- Geometry: The waterproofing membrane needs to have the flexibility to fit around your uniquely shaped roof. A liquid membrane would work best in this case because it can take any form. On the other hand, a sheet membrane can fold and crease, leaving gaps between the membrane and underlay.
施工步驟
1.先鏟除舊有天台防水層，再拆除原有的樓板。
2.樓板表面必須平整。
3.按比例混合天台防水底漆。
4.在天台防水層底漆用油掃或油轆塗刷第一層，表面塗上最少1mm厚，將整個地台表面及天台圍牆牆身覆蓋。
5.底漆乾涸後，塗刷第一層聚胺脂天台防水物料，要以1mm的厚度。24小時後，以90度方向塗刷第二層聚胺脂天台防水物料，要1mm的厚度。
6.做好地台批盪及鋪天台隔熱。
7.天面磚及掃口需鋪回。
- Resistance to UV heat: Bituminous membrane waterproofing won’t lose its integrity in warm, sunny climates.
- High elongation percentage: Most membranes must have an elongation of 150% to accommodate structural movements, so it’ll protect your roof, even if cracks develop.
- Excellent flexibility: A sheet made from bitumen is flexible enough to take any shape once laid. Since it has high flexibility, it won’t crack, dent or break in harsh weather.
- Resistance to chemicals: This type of waterproofing won’t deteriorate in the presence of debris or factory chemicals.
| 天台表層防水噴塗
防水噴塗施工前必須確認天台漏水源頭，及位置範圍，才可進行防漏工程。經常浸水部位不適用，適用範圍：斜屋頂面、垂直壁面或不會積水的地台。
施工步驟
1.天台地台有沒有鬆脫的空鼓要先確認。
2.用高壓水槍、吸塵機、掃把等，將天面清潔好。（如有天台防水塗層，需鏟除破損）
3.必須確保施工前3天沒有下雨，天台表面也完全乾燥。
4.天台防水底漆的比例要拌勻。
5.在天台防水層底漆用油掃或油轆塗刷第一層，表面塗上最少1mm厚，將整個地台表面及天台圍牆牆身覆蓋。
6.底漆乾涸後，塗刷第一層聚胺脂天台防水物料，要以1mm的厚度。24小時後，以90度方向塗刷第二層聚胺脂天台防水物料，要1mm的厚度。
7.等24小時後防水膜會完全乾燥。
- Clean out the substrate: Cleaning the surface allows a liquid applied membrane to adhere well. Pressure-wash the substrate to clean it and remove debris, dust or grease that could compromise the adhesion. You can also inspect the roof for blemishes that affect its resistance to water damage.
- Prime the surface: Apply a primer to the surface to enhance the membrane’s adhesion. Primers can also prevent the bituminous oils from bleeding through to the membrane. Before the craftsperson applies the primer, they make sure the surface is dry. To speed up the drying process, they might use torches or an air blower.
- Treat the roof’s details: You must treat all components before applying the liquid membrane. These details include the interior and exterior corners, wall-to-floor corners, metal flashing terminations and penetrations — such as pipes, vents and drains. Embed reinforcing fabric into the liquid membrane, or use a flashing-grade sealant. Make sure you cure the materials before applying the coat of treatment.
- Apply the liquid membrane: Some liquid membranes need fabric reinforcing mats underneath before installation. The application, substrate porosity, temperature and waste affect the liquid membrane’s consumption rate. You might want to apply granules if you live in a warm climate, because they can keep your building cooler.
- Inspect the roof: In most projects, a craftsperson needs to inspect the application at each phase. They’ll check the primer’s coverage, the pull-out and mock-up, the detail treatments and the applied coating millage. They must consider the wet film thickness during application to ensure they use the right amount.
注意事項
基層處理 -確保基層表面堅固、無粉化、剝離等現象，是施工前要做好的基層處理。同時必須清潔基層表面。基層表面應平整、無明顯補痕、無缺陷。
基層表面裂縫 – 如不想日後發生裂縫位置斷裂，導致防漏失效，基層表面有裂縫須把裂縫位置鑿開成v形，用防水材料修葺。
防水層弱點補強 – 如橫直交接處及喉管過牆位置須要合適的補強，天台防水層必須保完整性，只要有一處裂痕或破損，則整個天台防漏失效。
防水層底漆 – 以下要求在塗刷天台防漏施工時特別重要。天台防水底油不能作防水材料，其效果為增強天台防水層與底漆的附著力，讓面漆更有效及持久。
保持地面乾燥 – 施工前可連續日曬，讓地面或牆面的水份完全釋出。
防水層必須分層施工 – 防水層必須分層及薄而牢固，天台防漏才會成功。成型的天台內不會表面乾燥，內部仍濕潤的情況發生，否則會導致防水層龜裂。
檢驗防水施工質量 – 浸水試驗(flood test)是防水檢查的重要工作。