Working in the rain can be challenging for anyone who works outdoors. Because most construction work, including concrete, takes place outside and not under a roof, the work is highly susceptible to weather changes. Is it possible for concrete workers to continue working in the rain?
Concrete workers don’t work in heavy rains and thunderstorms. Storms can cause poor visibility and lightning can be extremely dangerous. However, concrete workers may continue their work with adequate preparation and covers to keep the poured concrete safe while it cures in light rain conditions.
Read on to understand how rain affects construction work, concrete work in particular, and what you can do if you need to complete your concrete work during the rains.
Rainy Days in Construction
Generally speaking, rain and construction don’t mix well. When the rains begin, most people start planning their construction work until the rains stop. For the most part, construction workers avoid working in the rain as the construction site itself can become quite dangerous in the rain.
Heavy rains can muddy the ground, making it easy for workers to slip and fall. A downpour also affects visibility, which halts work. No construction work can happen in a heavy downpour or a thunderstorm as the risk of lightning is very high. In addition, working with electric equipment, such as drills, is also dangerous as the rain increases the chances of electroshock.
However, most concrete workers will continue working if the rains are mild. Concrete needs to be cured, not dried. Therefore, in the rains, the workers can manage the concrete curing process by covering it using tarpaulin.
Nevertheless, pouring concrete in the rain isn’t easy. If possible, the work of mixing and pouring concrete should be reserved for days when there’s no rain. Pouring concrete in the rain comes with its own challenges as concrete is quite sensitive to rain.
What Happens if It Rains After Pouring Concrete?
Heavy rains on freshly poured concrete will affect the strength of the concrete as the water will dilute the mixture. This dilution will increase the chances of dusting and scaling. Water that seeps underneath the concrete or pouring from drainage will also ruin the final finish.
Concrete absorbs water, and the material needs hydration to turn fluid and become strong enough for use in construction. However, the ratio of water to concrete needs to be carefully maintained.
Too much water can dilute the concrete, making it weaker and prone to damage like dusting and scaling. The resulting slab will also be more fragile, and its strength will be compromised. This process where the rainwater mixes with concrete, affecting the water-concrete ratio, is known as ponding.
Any water underneath the concrete pour will affect how the concrete sets. When workers pour the concrete on wet ground, a phenomenon called bowing happens. The bowing is because concrete absorbs water and does so unevenly. The uneven absorption results in some slab parts absorbing more water than others, pushing the more hydrated portion up.
The rains can also cause water to pour in streams from drainage pipes, carving holes or channels into the freshly poured cement, affecting the final finish.
Water can also affect freshly finished concrete. If any water gets under the sealing material, it might bubble up, destroying the finish of the slab.
While construction workers can mix and pour concrete with some success in light rain, they must take several precautions to ensure that the concrete pour is successful.
Read more: How Long After Pouring Is Concrete Safe From the Rain?
Concrete Work in the Rain
As a standard rule, concrete and other construction works don’t work in heavy rains. The conditions will be too dangerous for workers, and the concrete itself won’t cure well.
However, if you must finish up your concrete work in the rainy season, you can take some measures to complete the work without affecting the workers or your site.
Scope Out and Cover the Construction Site
The first step to carrying out concrete work in the rain is to scope out the construction site. You can be preemptive and set up these covers before the rain starts. Check if the ground is completely dry, then set up coverings so your concrete pour won’t get wet in the rain.
If the ground is wet, wait for the ground to dry out before you start work. You should not use dry concrete to soak up the water because this will create unevenness in your final pour. An uneven concrete pour will result in an uneven finish on your concrete slab.
Watch out for any spouts or gutters that might pour draining rainwater directly onto your concrete. If you detect any spouts, redirect them or adjust your tarp to protect your slab. Ensure that you have extra tarpaulin available for anything that might need to be covered in the event of a sudden downpour.
When you cover the slab, ensure that you cover the edges as well so that water doesn’t seep underneath the slab.
How Do You Cover a Construction Site in the Rain?
The best way to cover a construction site in the rain is to use a tarp or plastic sheets. You can erect temporary shelters that are large enough to cover the construction area. You should also cover any freshly poured concrete using tarpaulin or plastic.
Remove Excess Water When Finishing
If the top of your concrete slab has a layer of water on top while you’re finishing it, use a brush, a squeegee, or a float to remove the water from the top before you continue your work.
As long as the finishing process is complete, a little water collecting on top of the slab won’t be a problem.
It may even support the curing of the concrete and help it cure faster. In extremely dry climates, wet sacks are placed on top of curing concrete slabs to ensure that they cure well.
Get Workers Wet Weather Gear
If your concrete workers get sick, your work will get delayed even further, and you might have to pay towards their missing workdays.
In a situation where you need to continue construction in the rain, in addition to covering the work site, you should also ensure that there’s sufficient wet weather gear available to your workers.
Fixing Rain-Damaged Concrete
Rain can damage concrete in many ways. The concrete itself might become oversaturated in a process known as ponding, where the ratio of water increases in the concrete to water mix. This weakens the concrete and makes it brittle. The color on colored concrete may wash away, dusting or scaling might be seen on the finish. The slab may even crack.
In severe cases, there’s no rescuing the damaged concrete. Ponding and bowing of the slab are disastrous, and the only solution to that would be to redo the concrete in that area.
However, if the damage is only on the surface level – like dusting, scaling, or color loss – it can be fixed without redoing the entire slab. In such situations, the concrete’s top layer needs to be scraped off; then, fresh concrete can be mixed and poured on top in an overlay.
Concrete is sensitive to water, so concrete workers typically don’t work in the rain. In heavy rains, no work is possible. However, concrete can be poured in light rain in a pinch. To ensure the success of your pour, you need to make sure that the site, concrete slab, and the workers are all covered adequately to protect them from rain damage.