- Can you pour concrete over weeds?
- How many square feet does an 80lb bag of quikrete do?
- How many inches of gravel do you need for a concrete slab?
- What is the best gravel to put under concrete?
- How thick does a concrete overlay have to be?
- Should you put plastic under concrete?
- What happens if it rains after pouring concrete?
- Do you need rebar for 4 inch slab?
- How do you attach concrete to old concrete?
- Can you put mulch over cement?
- Will a tree stump grow under concrete?
- How do you stick new concrete to old concrete?
- Can you pour concrete over dirt?
- Can you pour fresh concrete over old?
- Is gravel necessary under concrete?
Can you pour concrete over weeds?
You can, but shouldn’t.
It depends on how big of a slab you are pouring and what you intend to put on top of the slab.
Best practice is to remove all vegetative material from underneath any pour because it will deteriorate and allow space between the soil and concrete which, in turn, reduces the support underneath..
How many square feet does an 80lb bag of quikrete do?
15 cubic feet for every 20 pounds of mix, so a 40-pound bag yields . 30 cubic feet, 60 pounds of concrete mix yields . 45 cubic feet and an 80-pound bag yields . 60 cubic feet.
How many inches of gravel do you need for a concrete slab?
Excavate the slab area to a depth of about 7 inches, allowing 3 inches for a gravel base and 4 inches for concrete.
What is the best gravel to put under concrete?
Backfill beneath concrete flat-work along foundation walls should be accomplished with a granular material that is uniform in size. Some fill materials, such as round stones like pea gravel, tend to be self compacting. “I recommend open-graded granular material be used,” says Tull.
How thick does a concrete overlay have to be?
25 to 50 mmThe minimum recommended thickness is 1 to 2 in. (25 to 50 mm) for a fully bonded concrete overlay placed on a base slab that is practically free of cracks and in which the concrete is sound, clean, and of good quality. The use of welded wire fabric reinforcement is usually not warranted under these conditions.
Should you put plastic under concrete?
Recently, though, research has shown that the old traditional layer of 6-mil Visqueen (polyethylene plastic) under the slab is seldom effective for two main reasons: Although it may seem water-tight, this grade of material allows a lot of water vapor to pass through.
What happens if it rains after pouring concrete?
Pouring concrete in the rain can compromise its strength, increasing the tendency for dusting and scaling to develop. Once the damage is done, it can be hard to rectify and will often ruin the appearance of the finished surface.
Do you need rebar for 4 inch slab?
No, you do not need rebar for a 4-inch slab of concrete on grade. A 4-inch-thick slab cast on the ground and in permanent contact with it will float and rebar is not required. Rebar is recommended on concrete measuring 5 – 6 inches thick.
How do you attach concrete to old concrete?
Drill 5/8-inch diameter holes six inches deep into the old concrete. … Flush the holes with water.Inject epoxy into the backs of the holes. … Insert 12-inch lengths of rebar into the holes, twisting them to ensure an even coating of epoxy around their circumferences and along their lengths within the holes.More items…
Can you put mulch over cement?
If you make the mulch deep enough and check the condition of the concrete after each winter, you should be fine. Additionally, you can plant pots of flowers to put out among the mulch and even put over any large cracks. For unwanted plants & weeds please use vinegar or w/ salt added.
Will a tree stump grow under concrete?
Large tree stumps may take around 10 years to fully decompose. However, as they decay under the soil, they cause the ground to settle. A concrete slab placed over a tree stump then, will eventually crack in several places, rendering the building, driveway or path that you construct useless.
How do you stick new concrete to old concrete?
Start by cleaning the older concrete with a strong acid wash. Then, prepare a bonding slurry to ensure the new concrete adheres to the previous layer. Dampen the existing concrete, apply the bonding slurry, then add your new concrete.
Can you pour concrete over dirt?
Long story short, yes you can pour concrete over dirt.
Can you pour fresh concrete over old?
If done properly, new concrete can often be poured right over an existing slab. For this to be feasible, the contractor needs to pour at least 2 inches thick, use smaller aggregate, and incorporate reinforcement such as welded wire mesh or fiber mixed into the concrete.
Is gravel necessary under concrete?
Whether you pour concrete for a walkway or patio, a strong gravel base is required to prevent the concrete from cracking and shifting. Gravel is especially important in clay soil because it doesn’t drain well, which results in water pooling under the concrete slab and slowly eroding the soil as it finally drains.