Concrete floor installation in Portsmouth NH - a floor ready for what goes on top
Cracked, damp or bare dirt floor in the basement or garage? We lay a new slab on a solid base, ready for your flooring.
- Fully licensed and insured.
- Free estimates at your property.
- We respond within 1 business day.
What goes into a new concrete floor in Portsmouth?
The short answer: Concrete floor installation from Portsmouth Concrete Works gives your basement, garage or shop in Portsmouth, NH a new slab on a packed base, with a moisture barrier under it so the floor and whatever covers it stay sound.
Most calls start with a basement floor that's cracked, damp or still bare dirt, or a garage or shop that needs a floor you can count on. The price moves with the floor's size, how much old concrete or dirt has to come out, how easy it is to get concrete to the spot, the base and moisture barrier your flooring calls for and the finish you want, and if the old slab has to be opened up first, concrete cutting adds to it. The schedule turns on the season, any permit question and curing, the wait while new concrete gains strength before your flooring goes down. Your written estimate puts your own figure on all of that.
How do you know your floor is due for new concrete?
Cracks that keep growing
Cracks that widen, or pieces that sink or lift at the edges, usually mean the dirt under the slab settled or washed out. Waiting lets new flooring crack right along with it, and the loose edges become something to trip on.
Damp spots or musty smell
Dark patches, white powder on the surface or paint peeling off the floor usually means ground moisture is coming up through an old slab with nothing under it to stop it. Lay carpet or wood over that and it can lift, stain or grow mold.
Bare dirt or patched floor
A dirt floor, or patches poured over patches, won't hold up once you finish the space or park on it. Covering it as it is means paying for flooring twice, so the floor underneath is the place to start.
How we handle concrete floor installation
Most floor decisions come down to what's going on top, so I ask about your floor covering early and we plan the moisture barrier to suit it. From there our crew takes out the old floor or the loose dirt, checks where the water runs, and digs out and packs the subgrade, the soil the slab sits on, with a compacted stone base over it so the floor doesn't settle later. The barrier goes down next, then the reinforcement, the steel or wire that holds any cracks tight, and then we pour and finish the surface to suit your flooring. We cut control joints, shallow saw lines that give the slab a planned place to crack, while the concrete is still young, and we keep it damp while it cures. If the budget gets tight, I'd rather you go plainer on the finish than cut corners on the base, because nobody sees the base on day one but it decides whether the floor stays flat.
A new floor often comes with other work. If the floor changes the height at a door, new concrete steps can make the trip in and out easier, and outside, a concrete pool deck takes the same care with the base and the water.
Under carpet, wood or vinyl
This suits a basement you're finishing into living space. These coverings trap moisture against the slab, so the barrier choice matters most here and we finish the surface smooth and flat for the flooring installer.
Under tile or stone
Tile shows every dip and hump, so flatness is the main goal. We talk through the tile layout before the pour so the joints land where they won't fight it.
Left bare or coated
This suits garages, shops and utility rooms. We can trowel it smooth for a coating or give it a broom finish, light grooves that give your feet some grip where the floor gets wet.
What happens after you call about a concrete floor?
From the first call to the cleanup, here's who does what, so you know when I'll be at your house and what you'll have in hand before you decide anything.
- Step 01
Call or send a message
Call (603) 956-1034 or use the contact form, and we'll get back to you to set up a time for me to come out.
- Step 02
I walk the space with you
I come out myself, look at the floor, the access and where the water goes, and ask how you'll use the space and what's going on top. Then I send a written estimate so you can see the work and the price before you commit to anything.
- Step 03
Settle permits and a date
Once you're ready, we sort out any permit questions and pick a pour date with the season in mind. A winter floor can be done, but it needs a plan for the cold, so we talk timing through with you.
- Step 04
Prep, pour, finish, clean up
Our crew preps the base, pours and finishes the floor, then cleans up before we leave. The floor needs time to cure before your flooring goes in, and we'll go over that wait with you.
Concrete floor installation rules in Portsmouth
Portsmouth's Inspection Office issues building permits for new construction and general renovation, and its list names additions, structural changes and garages but doesn't mention concrete floors, so whether your new floor needs a permit isn't settled until you ask the city. State law also says every building and structure built in New Hampshire has to meet the state building code and fire code. Repairing a floor that's already there is a different case, because the city needs no application or notice for ordinary repairs unless the total cost of the repair work runs over $3000. Before we set a pour date, we check what the office needs for your job and help pull together the sketches, site plans or drawings they ask for.
Around Portsmouth we see a lot of older basements with thin, cracked floors or bare dirt, and garages where water finds its way in under the door, so I look at where the water goes before anything else. We see the same kinds of floors on jobs in Dover and across the river in Kittery, since we work in the cities around Portsmouth on both sides of the Piscataqua River.
Get a free on-site estimate for your concrete floor
We respond within 1 business day to set up a visit. I come out, look at the space and send you a free written estimate, with no pressure to book.
Why Portsmouth homeowners call Portsmouth Concrete Works
I'm there from estimate to pour
I come out to look at the job and write the estimate myself, our own crew does the work, and I'm on site for the pours. The person who heard what you need is the one watching the concrete go down.
Running this business since 2017
I poured my first concrete patching barn floors on our family farm, then spent years on other crews learning flatwork and foundations before starting Portsmouth Concrete Works in 2017. We're known for the awkward jobs, like old slabs that need opening up, and I'd rather puzzle over a tricky spot than leave you a problem.
Fully licensed and insured
Portsmouth Concrete Works is fully licensed and insured. A floor job puts our crew and equipment inside your basement or garage, and that's not something you should have to wonder about.
Historic and flood areas planned early
Portsmouth reviews and approves building plans, and if your property sits in a historic or flood area, we plan around that review from the start. That keeps the pour date from slipping once the paperwork catches up.
On a floor, what's under the slab and where the water goes matter most, so send us a message or call (603) 956-1034 and I'll come take a look.
Concrete floor questions from Portsmouth homeowners
Will my new concrete floor crack?
Probably a little, and that's normal. The industry's national floor guide says some random cracking should always be expected, even with joints cut close together, and that reinforcement won't prevent cracks, though sized and placed well it keeps them tightly closed. That's why it's worth asking any contractor how they size and place the steel, and our work is backed by our satisfaction guarantee.
Where should the vapor barrier go under a concrete floor?
Placed directly under the slab, the barrier gives your flooring and any coating the most protection from ground moisture. The industry floor guide notes the trade-off, which is that the slab settles and shrinks more as it dries, so that placement takes extra care in design and pouring, and it also keeps water from rain, saw-cutting, curing or cleaning from getting trapped in the fill below. The same guide says the ordinary thin plastic sheeting used in the past shouldn't be considered for this, which is part of why your flooring choice comes first.
Can you pour a concrete floor in a Portsmouth winter?
Yes, a winter pour can still reach enough strength and durability when the concrete is properly mixed, placed and protected. National cold-weather guidance treats it as cold weather when the air drops, or is expected to drop, below 40°F while the new concrete is being shielded from the cold, so the plan has to cover that whole stretch and not just pour day. We work that into picking the date.
What causes a new concrete floor to get dusty?
A weak top layer causes it, and it usually comes from finishing in heat that dries the surface too fast or from running unvented heaters during a winter pour. Industry guidance says fuel-burning heaters give off carbon dioxide that can leave a weak surface that dusts under traffic, so they should only run vented outside the heated enclosure during placing, finishing and the first 24 to 36 hours of curing. If your floor goes in during the cold months, ask how it will be heated.
How much does a new concrete floor cost in Portsmouth NH?
The price comes down to the floor's size and what it takes to get it built, and you'll get your own figure in the written estimate after I see the space. Taking out an old slab or digging out dirt, tight access into a basement, extra base work, the barrier your flooring needs, the finish and a winter pour that needs heat and protection all push it up. A simple, open garage floor with good access usually sits at the lower end.
How do I get a building permit in Portsmouth NH for a concrete floor?
Portsmouth's inspection office issues the city's building permits and takes applications for all city inspection permits online through its ViewPoint system. Inspections are booked by calling the Inspections office at 603-610-7243 with the permit number, the address and the kind of inspection you need. Whether your floor needs a permit at all is the first thing we check, as covered above.
Related concrete work around a new floor
Concrete steps construction
If your new floor sits lower or higher than the door, solid steps make the trip in and out with laundry or tools safer and easier.
Concrete pool decks
A pool deck needs the same packed base and planned drainage as a floor, plus a surface that gives bare feet grip when it's wet.
Tell us about your new floor
Call (603) 956-1034 or use the contact form with the floor's size, whether it's a basement or garage, the flooring you want and your timing, so I show up with the right questions.