Concrete cracks are quite disturbing, especially in newly built houses, but not all of them are a source of trouble. Some are simply normal and happen to the concrete as it dries and settles. The vital thing is to recognize which ones are normal, which ones need to be monitored, and which ones require an immediate fix.
This article will help you figure out why concrete cracking in new buildings, what types of cracks are considered normal, how to keep them from happening, and how to best protect and repair your concrete.
Why Do Cracks Appear in New Buildings?
New concrete cracks majorly because of the following reasons:
- Shrinkage: As concrete dries, water is released to the air. A small volume of the concrete is what causes the thin cracks.
- Thermal movement: Warmth promotes expansion, while cold causes contraction. Temperature change differentials cause the slab to be under stress.
- Insufficient curing: If the concrete dries out very quickly, it loses moisture unevenly and surface cracks appear.
- Overloading: Heavy machines and construction work carried out on the site before the concrete is fully cured can result in crack formation.
- Poor Mix Design: A mix that is too wet or without the right types of aggregates will weaken the structure’s solidness.
Types of Cracks in Concrete
These are the types of cracks you can observe at home:
Plastic Shrinkage Cracks
These occur within hours after the pouring process. They are thin, a few millimeters deep, and sometimes take the form of a spider web-like pattern. They develop when the drying rate of the surface is too high due to the sun or wind.
Settlement Cracks
Settlement cracks occur when concrete settles on an uneven subgrade. Generally, you spot them around columns, walls, or heavy footings. Temperature changes can cause the slabs to expand or shrink, thus resulting in diagonal or vertical cracks. These could have been prevented with the correct use of control joints.
Structural Cracks
These are more profound and serious. In general, you find them on beams, slabs, or load-bearing walls. If not taken care of, they can weaken the stability of the structure.
Crazing and Map Cracks
They are surface cracks that draw attention to the facades of the building more than the strength, but with time, they can become a means for water absorption.
The Influence of Moisture and Waterproofing
For newly-built houses, the use of waterproofing materials that act as a barrier to water penetration and, at the same time, allows the concrete to ‘breathe’ is recommended.
Polyurethane Waterproofing
Due to its flexibility and great adhesion, it is the most appropriate material for fine crack and joint sealing applications. The use of roof, basement, and polyurethane waterproofing is the best solution.
Bitumen Waterproofing
The implementation of bituminous coatings and membranes on foundations and slabs is the commonly adopted cost-effective solution. Besides, bitumen waterproofing acts as a guard against moisture and chemical exposure.
This means that waterproofing admixtures are added directly to the concrete mix. Integral waterproofing is always the most efficient as it comes from the inside and lasts for a long time.
FAQs
Do new concrete structures always develop cracks?
Yes, tiny hairline cracks due to shrinkage and temperature changes are normal. These cracks rarely imply structural damage, however, and thus should only be checked regularly.
How do I know if a crack is serious?
If a crack is wider than 2 mm, structurally continuous, or accompanied by water seepage, it indicates that the structure might be distressed; therefore, promptly seeking the advice of an engineer will be a wise choice.
How can I permanently fix the cracks in my concrete?
When cracks emerge, refrain from waiting until they get bigger; early detection, smart repair, and permanent protection are the ways to go.
Build Stronger with Sealbond!
Cracks are threats to building your future home because it is the investment you want to last longer. Sealbond, a company delivering trusted waterproofing materials, concrete binders, and structural repair systems for crack and leak prevention, is widely used by builders across the country. Contact us today and let’s work on your cracks together!
