Sealant for greenhouses: which one to choose?
Some manufacturers of greenhouses include sealing materials in sets of finished products, this is not provided by other companies. A summer resident buying such a design needs to decide whether to purchase an additional insulation kit or whether you can do without it. This article will help to understand what are the pros and cons of rubber and other gaskets, as well as why they are needed.
What is it needed for?
When assembling a greenhouse at the junctions of polycarbonate sheets and at the ends of the structure, cracks and gaps may form that allow moisture and dirt to pass in and heat to go out. In addition, debris and moisture also penetrate into the open polycarbonate honeycomb, due to which the material is destroyed. The listed problems are solved by the use of gaskets. Ends closed with rubber or other gaskets keep the greenhouse airtight, extend its life and help create a microclimate suitable for plants.
Did you know? Elastic rubber is obtained as a result of the vulcanization process. This recipe was accidentally discovered by Charles Goodyear, who mistakenly heated rubber mixed with sulfur on a stove.
The group of rubber seals include rubber, silicones and thermoplastic elastomers (thermoplastic elastomers). These materials are flexible and dense, can have a porous and continuous structure. Depending on the purpose of use, they come in 3 types:
- Additional material is filled under a metal or plastic profile, providing it with reliable sealing and at the same time allowing polycarbonate to react to temperature changes.
- Self rubber profile.
- U-shaped seal that is inserted inside the end profile to securely close the polycarbonate honeycomb.
Advantages and disadvantages
- The rubber seal has the following advantages:
- low price in comparison with other materials;
- flexibility allows the use of material in curved arched structures;
- ease and universality in use;
- protects the microclimate of the greenhouse from weather changes, retains moisture and heat 30% better;
- reduces vibration of polycarbonate sheets from gusts of wind that can destroy the material;
- does not allow moisture, pollution and insects that can penetrate the greenhouse and damage the crop;
- gives the greenhouse an aesthetic look.
- There are also disadvantages to rubber:
- deforms with time;
- collects condensate;
- at low temperatures hardens, loses elasticity, becomes brittle.
For the ends of the greenhouse, an h-shaped rubber or TEC sealant is often used. It is used as an independent profile, and not an additional material. His set when the polycarbonate sheets are already attached to the frame, but not yet screwed to the end pipes. Rubber is carefully put on the end of the sheet along the entire length. After that, the polycarbonate is screwed to the end. Then a wall sheet is attached to the same pipe. As a result, the end face around the perimeter is hermetically sealed with a rubber profile.
Did you know? In South America, a hevea tree grows, from the juice of which natural rubber is made. Local Indians adapted to the rapid manufacture of waterproof shoes: they dipped their feet in fresh juice, which after solidification became rubber galoshes.
If a U-shaped seal is used, then it is inserted inside a metal or plastic profile. Then he puts on the end of the polycarbonate, closing his honeycomb. And only after that the sheet is screwed to the frame.
In addition to rubber seals, other materials can also be purchased for tight joints and polycarbonate protection. Among them:
- profiles (aluminum and plastic);
- tapes (sealing and perforated);
- thermal washers;
- various sealants.
Plastic profiles are lightweight, durable and quite flexible. Great for joining multiple polycarbonate pieces. They are often used in the assembly of arched, domed and rectangular greenhouses.
Important! It is better to use transparent polycarbonate profiles. They do not give undesirable shading and do not spoil the general view of the polycarbonate greenhouse.
Depending on the application, the following types of profiles are distinguished:
- stub - a profile that covers the ends of polycarbonate sheets;
- one-piece profile - connects two pieces of coating with each other and attaches them to the frame, designed for a certain thickness of the sheet;
- split profile - serves as a connecting element for sheets of different thicknesses, because it is laid out on the base and cover, and also attaches the coating to the frame;
- ridge profile - connects roof slopes, suitable for a gable greenhouse;
- corner profiles - connect the sheets of walls at the corners of the structure.
Aluminum profiles are strong and durable. They can connect not only lightweight polycarbonate sheets, but also pieces of heavy glass. There are as many varieties of metal elements as plastic ones.
Such designs are so reliable that they are often used as load-bearing. But they usually need additional compaction from a soft and elastic material, such as rubber or silicone. Although modern models are already produced with rubber and silicone layers. The disadvantage is the shadow that aluminum profiles cast on the plants.
Due to the high cost of thermowells are not used so often. Rubber, metal and even wooden gaskets remain more popular.
- But their thermowells are in many ways superior:
- durable material, serves up to 20 years;
- excellent tightness: does not pass neither heat, nor rainfall with garbage, nor dust with moisture in polycarbonate cells;
- It reacts remarkably to weather changes and perfectly adapts to temperature expansion and narrowing of holes for self-tapping screws, so it does not lose its airtight properties.
Important! To thermowells reliably fasten the structure and maintain tightness, they must be correctly selected. The length of the legs of these parts should correspond to the thickness of the polycarbonate.
Thanks to these characteristics, thermal washers extend the life of the entire greenhouse. At the same time, the money spent on premature repairs when using cheaper gaskets is saved.
Self-adhesive tapes resemble adhesive tape. They are designed to seal the ends of polycarbonate sheets.
- Material Advantages:
- tightly glue the polycarbonate honeycomb, not letting moisture and dust from the outside;
- have protection against ultraviolet rays;
- easy to stick, can be glued;
- durable (10 years).
Two types of tape are used to seal the polymer:
For perfect sealing it is recommended to use tapes together with metal or plastic profiles.
The most budgetary option for seals are building glue and silicone sealants. Use is quick and easy. But it is better to use them only if urgent repair is necessary or the cracks formed are closed. Since sealants have a short service life, over time it is worth replacing them with more reliable materials for sealing.
Each of the above sealing elements has pros and cons. Choosing gaskets for the greenhouse, you need to take into account some important factors:
- greenhouse coating material;
- insulation quality;
- financial opportunities.
Here are some guidelines:
- For a heavy coating of glass, it is better to take the most reliable aluminum profiles, but they need additional rubber or silicone layers.
- Of the cheap gaskets, the highest quality are special sealing tapes, but for guaranteed sealing it is advised to use them together with profiles.
If you want to use elastic material for sealing, ordinary rubber should prefer TEP, since this material does not deform, does not deteriorate from ultraviolet radiation and ozone, and also withstands frosts down to -40 ° C.
Having learned what seals are, why they are needed and what are, you can make the right choice. It is important to remember that if you cheapen at the beginning, you can pay dearly for premature repairs.