For building construction, the test brought by summer. One is the soaring temperature and the other is abundant rainfall. The suitable conditions for putty construction are that the temperature is 5-35°C and the air humidity is less than 85%.
As an essential process of wall construction. If there is a problem with the construction effect of the putty layer, the overall effect of the exterior finish layer will be greatly reduced.
What are the problems that may be faced in construction in such an environment? In order not to let the environment affect the construction of putty, what should we do?
01.Dry too fast
Putty powder dries quickly when it is mixed in a barrel, making it difficult to construct. After batch scraping, the water loss is fast, and the surface of the putty dries too quickly, which leads to the failure of normal pressure after construction.
[Reason] The temperature of the construction environment is too high and the humidity is too low. Excessive ventilation and direct sunlight. The composite material reaction in the putty is accelerated.
[Solution] Prevention first, pay attention to the construction environment. Avoid construction during high temperature periods and direct sunlight periods. Control the ventilation intensity of the construction site. When the base surface is too dry and absorbs water quickly, it is recommended to brush the interface agent or pre-wet the base surface (but no clear water) before construction.
02.Batch scraping and rolling
When the putty is scratched and compressed, it will be lifted or scaled.
[Reason] The base surface is too dry or the temperature at the construction site is too high.
[Solution] When the base layer is too dry, it should be applied with moisture. Avoid construction during high temperature periods such as noon. For batch scraping of the putty that has been turned over, the putty should be removed. Apply the sealing material and then scrape again.
Bubbles are generated when the putty is scraped or the surface is blistered after scraping.
[Reason] The temperature is high in summer, the base layer is too dry for construction or the putty is dry on the outside and not dry on the inside, resulting in air bubbles.
[Solution] Wet the base layer and scrape it. It should be ensured that the first layer of putty is completely dry before batch scraping the surface layer of putty. When preparing the putty, it should be fully stirred as required. Construction in a suitable temperature range. If there are bubbles in the putty when scraping, you can repeatedly compress the putty when the surface is dry to eliminate the bubbles.
04.Powder falling and delamination
After the construction is completed and completely dried, the powder will fall off when touched by hands. In severe cases, there may even be peeling between the two putties before and after or between the putty and the substrate.
[Reason] The putty is applied when it is dry at high temperature, and the water evaporates quickly. There is not enough moisture for curing, so it is easy to powder. However, the bottom layer of putty is loose and pulverized, and the surface layer of putty is too hard. Drying too quickly can cause delamination. In addition, after the putty on the exterior wall is washed by rainwater, the adhesive will be lost, and it will be easy to delaminate after being reapplied.
[Solution] Construction in high temperature, dry and strong wind weather. It is best to wet the base surface with ignorant water before putting on the putty construction. The construction should be compacted and compacted. Moderately master the drying time. Specific analysis of the specific situation:
1. After the inner wall water-resistant putty is coated with a sealing primer, the strength will increase. Generally no further treatment is required.
2. The external wall putty should strictly implement moisturizing construction. Avoid direct sunlight for construction. After the putty on the surface layer is dry, sand it in time and moderately, and fully water it for more than 2 times.
3. The surface of the calendered putty should be thinned with another layer of putty. And carry out calendering treatment in time.
There are cracks in the putty layer, and the cracks are divided into regular linear cracks, “T-shaped cracks”, network cracks, large cracks, irregular short-line cracks, local small cracks, and many vertical short-line cracks at the inner corners wait.
[Reason] Single-pass scraping is too thick. Dry too fast. Don’t be dry on the outside. Of course, there are many kinds of cracks, mainly as follows:
1. There are regular linear cracks, mainly at the cracks.
2. “T-shaped cracks” and “reticular cracks” are mainly base cracks.
3. Large cracks and irregular short linear cracks are mainly dry cracks where the putty is scraped too thickly.
4. There are many vertical short-line cracks at the same time, mainly because the base layer is too loose or the corner repair putty is too hard and too thick.
[Solution] The putty is severely cracked and needs to be scraped off and reapproved. If the structure is loose, the construction shall be carried out after the structure is stabilized. Seam cracking should be treated in advance and then scraped putty.
Sheng Laiou is one of the largest cellulose ether producers in China.
HPMC, HEMC, HEC, EHEC produced by Sheng Laiou are used as additives for putty powder.
It has the characteristics of high condensation temperature and wide viscosity range. Effectively improve construction problems in different environments.
HPMC for wall putty/skim coat