REPAIRING OUTDOOR CONCRETE SLABS, DRIVEWAYS, YARDS AND HARDSTANDINGS
During the winter months your outdoor concrete surfaces take a battering from the weather. Rainwater seeps into any minor defect, dent, imperfection or hairline crack. Then, when temperatures drop, this water turns to ice. When water turns to ice it expands, pushing against the concrete and forcing cracks and gaps to open up further. That little hole gets a tiny bit bigger and those cracks get a tiny bit wider. When this happens time and time again the damage to the surface of the concrete starts to become noticeable.
If left untreated the damage could go on to effect the integrity of the slab. If this happens the whole section of slab may need to be fully replaced. This takes more time, effort, downtime and cost; so it is well worth carrying out a surface repair before this happens.
FACTORS TO CONSIDER WHEN THINKING ABOUT HOW TO REPAIR CONCRETE DAMAGED BY FROST:
The extent or type of damage:
The type and amount of traffic across the concrete surface:
The window of opportunity to carry out the repair:
A STEP-BY-STEP GUIDE TO REPAIRING FROST DAMAGED CONCRETE, CONCRETE DRIVEWAYS AND GOODS YARDS
Step 1: Preparation
Prepare the damaged concrete surface in accordance with the instructions on the product data sheet. Different products have different preparation requirements, so if you haven't worked with a product before please ensure you read the data sheet first.
Almost all products require you to remove all loose concrete from the damaged area and ensure that there is no dust, dirt, grease or any contaminants, such as oil and petrol.
Some products require the area of damaged concrete to be saturated with water, while others will not work on a wet surface. Even if the product requires a saturated surface, very few work effectively if standing water is left on the surface. Any surface water must be removed unless otherwise stated on the product data sheet.
Other products will fail if there is too much moisture in the concrete, so again - be sure to check the datasheet.
Furthermore, some products may require you to saw cut around the area of damaged concrete and breakout to the greatest depth of damage. And many products require the surface to be repaired to be abraded to ensure there is a good key for the repair materials to fix to.
When repairing large surfaces, it is better to divide the area into smaller sections with timber formwork - the formwork should also be used on top of movement joints and slab perimeters.
Step 2: Prime
Many concrete repair materials require a primer, but not all. Primers a usually liquids or slurries that are applied to the sound surface of the concrete that you have prepared. The primer helps adhesion and bonding between the existing surface and the repair materials.
Step 3: Mixing
Mix the repair material in accordance with the product data sheet. Some materials are extremely sensitive and it is imperative that the exact proportions of components are mixed as instructed. If you are unsure about the requirements for any products we have supplied, please call us to discuss on 01925852225.
Step 4: Applying
Depending upon the type of material and specific product the application method will vary. Some can be brushed or rollered, others poured and raked or trowelled. Instructions for methods of application are given on the product's data sheet, so again, it is important to review the data sheet.
Also review the product's data sheet for the minimum and maximum application thickness and/or number of coats or layers required/permissible. Plus, make sure the product can be used in the exact weather conditions you are going to lay the repair material in. When experiencing extremes of temperature, often below 5°C or above 30°C, some products will not perform properly; similarly, wet conditions may prevent application.
Step 5: Curing
Ensure you have reviewed the curing times on the product's data sheet. If conditions are particularly warm and/or windy you may need to protect the repair material by covering with sheeting, such as wetted hessian or polythene. This will prevent the material from curing too quickly, which leads to surface cracking. Only use liquid curing membranes should only be used an alternative way to control moisture loss if recommended on the product's data sheet. See Concreting Products . Equally some products will need to be protected from rain.
Stage 6: Trafficking
It's obvious, but don't stand, walk, cycle, wheel trolleys or drive of the repair before it cures. Once again, the product data sheet will give you curing times and the time after which the repair can be trafficked. They are estimated curing times because it will be affected by the weather conditions during the curing period. Many products perform optimally at 20°C, colder than this they will cure more slowly, above this they will cure faster. Some data sheets will differentiate between the amount of time after which the repair can accept pedestrian traffic, then light duty traffic, then heavy duty traffic.
FOR PRODUCTS, SEE: