When it comes to answering the question, “Can I pour new concrete over my existing stuff?” the cut-and-dry answer is “Yes.” But the real question should be, “Should I pour new concrete over my old?” Read on to see why the answer to that question is more complicated than you might think.
What to Consider Before Pouring New Concrete
Concrete patios and driveways can potentially last up to 50 years. However, your concrete’s thickness, the material components, and the amount of wear and tear determine its actual lifespan.
As your custom outdoor carpentry experts in the Denver area with over 25 years of experience, we can guess that if you are looking to redo your concrete patio or driveway, it’s highly likely it’s in a state of disrepair.
Before you pour over your existing slab, you must consider a few things—the first of those being your original concrete and the area you want to cover. The second consideration is the thickness a new layer will add to your original.
How Damaged and How Thick?
Unfortunately, damage to the original layer of concrete negatively affects a new top layer. Breaks and cracks in the original will end up as potholes or a broken and cracked top layer.
Furthermore, a new layer of concrete must be at least two inches thick. The added height can affect doorways, stairways, and garage entrance clearances. You or a professional will need to grade (slope) the new concrete so that you can still drive into your garage, open doors, and go up or down exterior steps without stumbling.
Check out the checklists below to determine if you should or should not move on with a professional or DIY project to pour new concrete over your old.
PROCEED, if you want to pour new concrete over old…:
- Stepping stones
- Sports court (e.g., basketball court)
STOP! And consider other options or consult the pros if you have…:
- Unresolved damage to your current concrete
- Tree roots growing up out of your existing concrete or would be in the way of a new pour job
- Considerable or massive cracks, breaks, or potholes
- Unlevel surfaces
- Doors or stairs that would be affected by the elevated level
If you checked any boxes under the “STOP!” category, it would probably be best for you to consider other options first, which we’ll talk about later in this article.
Know What You’re Getting Into
Even in the best of circumstances, pouring concrete can be tricky. Before tackling such a task, you’ll want to familiarize yourself with the necessary tools and steps to determine if it’s a worthwhile DIY project. You don’t want to risk doing this incorrectly and having to redo it again soon.
While we don’t have enough space to give a proper tutorial for concrete pouring in this blog, we can give you an idea of the necessary tools and supplies so that you have a decent idea of all it entails.
- Concrete boots and gloves
- Concrete rake
- Concrete mixer and bucket
- Rebar (reinforcing bar) or wire mesh
- Metal primer tape
- Bonding agent to adhere new to old or bond barrier to prevent it
- Hammer drill
- Pressure washer
- Perimeter material
Advantages of Pouring Old Over New
If your existing concrete is in relatively good condition, pouring new concrete over it can save you countless time and money.
Disadvantages of Pouring Old Over New
If you’re thinking about redoing your concrete patio or driveway, chances are there are potholes, cracks, or breaks you’re trying to remedy, and the concrete is not in good condition. As mentioned above, the flaws in your concrete will only resurface later, leading us to the first disadvantage of pouring new concrete over the old…
- A weakened top layer leads to short-lived results–The new layer of concrete will not have its full lifespan of 50-ish years. It’ll be much shorter because all the flaws and weak spots of the first layer will surface to the top.
- Increased height–Because the new layer needs to be at least two inches thick, the resulting slab will be considerably higher. The concrete must slope to avoid affecting steps, doorways, and garage clearances. The incline needed may be a troublesome fix.
Instead of pouring a new slab over an old one, consider patching damaged places and sealing your concrete to weather-proof it. For patios, consider shielding from sun, snow, and hail to mitigate wear and tear with custom patio covers.
Alternatively, you can have your concrete patio or driveway resurfaced. Resurfacing can update outdated colors, remedy discoloration, and fix holes, cracks, and breaks.
Unfortunately, sometimes the best solution is to completely tear up the old slab and start with a fresh slate. This is the most expensive resolution, but if underlying issues are causing an extreme case of disrepair, it can often be the least painful to fix problems instead of putting a bandage on them.
Need Help With Your Patio?
If you live in the Frontage area and need ideas for patios or patio covers, contact us at SRI Decks. We are experts on creating beautiful, long-lasting patios. Or if you simply need protection for your existing patio, our Denver custom patio cover builders can help you protect your outdoor living space.