Most Greater Houston homes sit on a concrete slab, and that slab shapes every kitchen remodel more than the cabinets or counters do. Moving a sink, adding an island with plumbing, or relocating a range all involve the concrete under your feet. Here is what to plan for, and what really drives the price, before you fall in love with a layout.
What the slab means for your kitchen
On a slab foundation, the drain lines run under the concrete. In a house on a crawl space, a plumber can slide underneath and reroute a pipe. On a slab, moving a drain means cutting a trench through the concrete, digging down to the line, and patching the floor afterward.
Layout changes are still possible on a slab. They simply cost more and take longer than most people expect. A kitchen that keeps the sink and dishwasher where they are is a very different project from one that moves them across the room to an island.
Supply lines and gas are easier. Water supply can often be routed through walls or ceilings, and gas lines usually run through the attic or walls. The drain is the stubborn part, because it needs a steady downward slope all the way back to the main line.
Moving the sink or adding an island
An island sink needs a drain that slopes to the main line under the slab, and it needs venting, which is harder in an island where there is no wall to run a vent pipe up through. There are approved ways to vent an island, and the right one depends on local code and the layout.
The distance between the new sink and the existing main line matters a great deal. A short trench is a modest job. A long run across the kitchen means more cutting, more digging and more patching, plus more time with the kitchen out of commission.
Before you commit, ask a plumber or contractor to locate the existing drain and main line. Sometimes a small adjustment to the layout, like shifting the island a foot, saves a lot of concrete work without changing how the kitchen feels.
Islands raise one more question: power. Code generally calls for outlets on an island, and a cooktop or microwave drawer in the island needs its own circuit. On a slab, getting wire to an island usually means sharing the plumbing trench or cutting a second one.
Post-tension slabs need extra care
Many newer homes around Houston are built on post-tension slabs, which have steel cables running through the concrete under high tension. Cutting one of those cables can be dangerous and can weaken the slab. You can often spot a post-tension slab by a stamp or warning near the garage or by the tendon ends along the slab edge.
Before any concrete gets cut in a post-tension slab, the cable locations need to be found, often with ground-penetrating radar or similar scanning. The trench path is then planned around them. Ask your contractor directly how they will locate cables before cutting.
Older homes may have conventionally reinforced slabs instead. Those still need care around rebar and the slab’s beams, but they do not carry the same risk. Knowing which slab you have is one of the first questions to answer.
Clay soil and an older drain line
Houston’s expansive clay moves with wet and dry seasons, and over years it can shift a slab and the pipes under it. In older homes, cast iron drain lines can corrode or crack, and sections may have shifted or sagged. A remodel that ties a new drain into a failing old line inherits the problem.
A camera inspection of the main drain before you start is a small step that can save a big headache. If the old line is in bad shape, it is far better to know before the new floor and cabinets go in than to find out from a backup six months later.
Also look for signs the foundation itself is moving: cracks in drywall above doors, doors that stick, sloping floors, or gaps at the baseboard. Long stone counters do not tolerate movement well, so a foundation issue should be checked before new countertops go on.
Permits in the city or the county
Moving plumbing, adding circuits or changing gas lines usually requires permits. Inside city limits, permits come from that city’s permit office. In unincorporated areas, the county or another local authority handles them, and the rules can differ.
Permits bring inspections at set stages, such as rough plumbing before the trench is backfilled and electrical before walls are closed. Planning the schedule around inspections keeps the job moving and avoids reopening finished work.
Interior kitchen work rarely needs HOA approval, though some associations want to know about construction traffic, dumpsters or work hours. Check your HOA’s rules before a dumpster shows up in the driveway.
What really drives the price
The biggest cost drivers are layout changes. Moving plumbing under the slab, relocating a range with a new gas line or vent hood duct, or removing a wall all add significant labor. Keeping the plumbing where it is saves more than almost any finish choice.
Electrical work comes next. Modern kitchens need dedicated circuits for appliances, more outlets on counters and islands, and better lighting. Older homes may need a panel upgrade to handle it. An induction range or a second oven can change the electrical scope by itself.
Then come cabinets, counters and appliances, which vary widely by choice. Custom cabinets, long stone slabs and pro-style appliances all push the number up. Surprises, like water damage behind an old sink base or a cracked drain line, are the last driver, and a good scope sets aside how those will be handled.
Living without a kitchen for a while
Plan for the kitchen to be out of service for the length of the project. Set up a temporary kitchen in another room with a microwave, a small fridge, a coffee maker and a folding table. Paper plates help when the only sink is in a bathroom.
Slab work creates concrete dust, and it travels. Expect plastic barriers, floor protection along the work path, and air filtration while the cutting happens. Pets and kids should stay well clear of open trenches.
Schedule around the hard parts. Concrete patches need time to cure before flooring goes over them, and stone counters are usually measured after the cabinets are installed, which adds a gap before the kitchen is usable again.
What hides under the old cabinets
Tearing out old base cabinets often uncovers a surprise or two. In many Houston kitchens the original flooring stops at the cabinet line, so pulling cabinets leaves bare slab, old vinyl or a different tile where the new layout needs a finished floor. If the new cabinets do not sit exactly where the old ones did, the floor has to be planned around that gap.
The sink base is the usual trouble spot. Years of small drips from a supply line or a dishwasher connection can rot the cabinet floor, stain the slab and leave mildew in the wall behind it. Once the cabinet is out, the wall gets opened if it is wet, the cause gets fixed, and the area dries completely before anything new goes back.
Walls behind old cabinets can be rough, out of plumb or patched from past work. New cabinets need flat, plumb walls to hang straight, and stone counters need cabinets that are dead level. Some shimming is normal. A wall that bows badly may need furring or new drywall, which is easier to handle while the room is empty.
Lighting and outlets for the way you cook
Kitchen lighting works in layers. Ceiling lights handle the room, under-cabinet lights put light right on the counter where you chop and read recipes, and pendants over an island add light where people gather. Many older kitchens have a single ceiling fixture, which leaves you working in your own shadow at the counter.
Plan outlets around how you actually use the space. Think about where the coffee maker, the mixer and the phone chargers will live, and put outlets there rather than at default spacing alone. Outlets near water need ground-fault protection, and an electrician will know what your local code asks for.
All of this wiring is easiest to run while the walls and ceiling are open. Adding a light or an outlet after the backsplash is set means cutting tile or running surface conduit, so walk the empty kitchen with your contractor at rough-in and confirm every box is where you want it.
Hood ducts, appliances and the order of work
A range hood only helps if it vents outside. Moving the range to an island or another wall means rerouting the duct through the ceiling or attic to an exterior cap, and a powerful hood may also need makeup air under local code. Plan the duct route early, because it affects ceiling framing and where the lights can go.
Appliance choices reach past the budget. A larger refrigerator may need a wider opening, a water line or a deeper cabinet. A gas range needs a gas line and a shutoff. A wall oven or a built-in microwave changes the cabinet layout. Pick appliances before cabinets are ordered, so the boxes fit what you actually buy.
The usual order runs demolition, slab and plumbing rough-in, electrical rough-in, inspections, drywall, cabinets, countertop measuring, counters, backsplash, fixtures and a final inspection. Each step waits on the one before it, so a delay in one, like a fabricator running behind, pushes back everything after it.
Keep your decisions ahead of the crew. A kitchen stalls fastest when the tile, the faucet or the cabinet pulls have not been chosen by the time they are needed. Make selections early and have materials on site before the step that uses them.
Getting a useful quote
A useful kitchen quote describes the layout, which plumbing moves and how far, what electrical work is included, how the slab will be cut and patched, and how unknowns get handled once walls and floors are open. Two quotes with very different numbers often describe two different scopes.
Ask whether the quote includes permits, the drain camera inspection, cable scanning for a post-tension slab, flooring patches, drywall repair and paint. Those items are easy to leave out of a low number and add back later.
If you are planning a kitchen on a slab and want an honest read on what your layout involves, call (832) 364-6271. Ask about financing through Acorn Finance and about the 10% discount we give military members and first responders.
Answer these before you pick finishes
- Whether the sink, dishwasher or range will move, and how far
- Where the existing drain and main line run under the slab
- Whether the slab is post-tension, and how cables will be located before cutting
- Results of a camera inspection on the old drain line
- Any signs of foundation movement before new counters go in
- Which permit office covers your address
- Where your temporary kitchen will be during the work
Questions
Can I add an island sink on a slab foundation?
Usually, yes. It means cutting a trench in the slab for the drain and planning a vent that works without a wall. The distance to the existing main line is the biggest factor in how involved it gets, along with whether the slab is post-tension.
How do I know if my slab is post-tension?
Look for a stamped warning near the garage or tendon ends along the slab edge, and check the home’s original paperwork. A contractor can confirm it, and the cables should be located by scanning before any saw touches the concrete.
Does keeping my sink where it is save money?
Almost always. Leaving the plumbing in place avoids cutting and patching concrete. Many good layouts keep the sink wall and change everything else, from cabinets and counters to lighting and the flow around the room.
Do I need a permit for a kitchen remodel?
If plumbing, electrical or gas work changes, usually yes. Whether the city or the county issues it depends on where you live. Swapping cabinets and counters in place, with no plumbing or wiring changes, often needs no permit at all.
Should I inspect my drain line before remodeling?
On an older home, it is a smart step. A camera inspection shows whether the line under the slab is cracked or sagging, which is much easier to fix before new floors and cabinets go in. The inspection takes a short visit and the video is yours to keep.
Leland or Geoff walks every job before anything gets decided. Book a visit, call (832) 364-6271, or look through the gallery first.