Patio Installation in Wayne, PA: Pavers, Stone, Drainage and Township Rules

A patio is the part of a backyard project you stand on every day, and most of what decides whether it lasts sits underneath it. We design and install paver and natural stone patios in Wayne and across the Main Line. One team handles the design and the build, so the patio that is drawn is the patio you get.

This page is for anyone planning patio installation in Wayne, Radnor, Villanova, Bryn Mawr, Gladwyne or King of Prussia. It covers the materials we install, how the base and drainage are built, how to size and lay out the space, what each township asks for before work starts, how a project runs, what drives the cost, and how a patio ties into walls, fire features, planting and the rest of the yard.

We are Mex Landscaping. Our Google profile, listed under the category Landscaper, showed a rating of 4.9 when it was read on October 3, 2026. The township rules, permit fees and state requirements on this page come from published sources, mostly the townships’ own documents and Pennsylvania state pages, and each one is named where it is used.

Paver and natural stone patios: the materials we install

The surface sets the tone for the whole space. We install concrete pavers in a wide range of colors and textures, natural flagstone and bluestone, travertine, clay brick and large-format porcelain. At the site visit we walk you through samples and recommend a surface that fits the style of your home, your budget and the way water moves across your yard.

Material	What we can tell you	Where it tends to fit
Concrete pavers	Many colors and textures, flexible patterns, and single units that can be lifted and reset. Pavers generally cost less than natural stone.	Clean-lined layouts, and patios where a future repair should be simple.
Bluestone and natural flagstone	Natural stone with a more traditional look.	Older architecture and established properties.
Travertine, clay brick and large-format porcelain	All three are on our list of installed surfaces. They are best judged from samples held against your own house.	Ask to see each one at the site visit.

Pavers or stamped concrete

We install both, and they age differently. Pavers flex through freeze and thaw, and a single unit can be lifted and reset, so a repair is simple and close to invisible. Stamped concrete is one poured slab, which can crack over time and is harder to repair without the patch showing.

The paver industry’s trade association, the Concrete Masonry and Hardscapes Association (CMHA), makes a similar point in its application guide for interlocking concrete pavements, tech note PAV-TEC-010. It says the joints between pavers help reduce the cracking typically seen in conventional concrete and asphalt, and that pavers do not rely on being one continuous piece for their structural integrity. Tell us how you plan to use the space and we will give you an honest recommendation for your property.

Who a patio project suits

We size and shape patios around real use: dining, lounging, a grill zone, a path to the door. A patio on its own is the right project when the yard is already close to level and what is missing is a firm, good-looking place to do those things.

It suits both ends of the local housing stock. On an established property the job is often to fit a patio without overwhelming the house, and bluestone or flagstone can complement older architecture. On a newer home, the patio may have to connect the back door to a yard whose grading was never finished.

It also suits people who want to build in stages. Many of our clients start with the patio and a fire feature and add a kitchen or other elements later. If that is your plan, say so at the start, because conduit and footings are far easier to place before the surface goes down.

When a patio alone is not the whole job

• The ground slopes. Level space may have to be made before anything is paved. Walls, tiered terraces and seating walls are covered under retaining wall contractor Wayne.
• You want a fire feature, a kitchen or a full outdoor room. The patio becomes the floor of a bigger project. See outdoor living contractor Wayne.
• The whole yard is being redone. Grading, drainage, paving and planting are then planned as one job, which is what backyard renovation Wayne covers.
• Water already sits in the yard. Drainage comes first. We build French drains, dry wells and regrading, and we would sooner fix a wet spot than pave over it.

Size and layout: how big, what shape, and where

Start from what will happen on the patio and work outward. A dining table, a place to sit, a grill and a clear walking line to the door each need their own space. At the site visit we plan the transition from the door to the patio and check how water crosses the site.

Shape is the next choice. Custom shapes, borders and inlays are part of what we build, and they change the price: a simple, level patio costs less than one with curves, walls, steps or a fire feature.

Size is not only a design question here, because township stormwater rules are written in square feet. The table shows the arithmetic for five footprints and what Tredyffrin Township’s application form says at each size. Upper Merion, Radnor and Lower Merion have their own rules, covered in the permit section below.

Patio footprint	Area	What Tredyffrin’s stormwater form says
12 by 16 feet	192 square feet	Can qualify for an exemption if impervious surface added since 2009 totals 499 square feet or less and the lot stays within its zoning limit
16 by 20 feet	320 square feet	Can qualify for an exemption on the same conditions
20 by 26 feet	520 square feet	Volume control required, with a site plan and stormwater management report
24 by 30 feet	720 square feet	Volume control required, with a site plan and stormwater management report
30 by 36 feet	1,080 square feet	Volume control and peak rate controls required

The cumulative rule matters. Tredyffrin’s form has the owner confirm that no other new impervious surface built since 2009 takes the total past 499 square feet. A 320 square foot patio on a lot that gained a 200 square foot addition in 2015 adds up to 520, which is over the line. Tell us about earlier work on the property at the first visit.

Base and drainage: what sits under the surface

Base preparation has a major effect on how a patio performs over time. We excavate to the depth the site calls for, install and compact a graded aggregate base, and plan drainage and slope so water moves away from the surface. Edge restraints and polymeric jointing hold the finished layout together.

The reason is the local weather. National Weather Service climate normals for Philadelphia show normal daily lows below freezing in December, January and February, at 31.2, 26 and 27.5 degrees Fahrenheit. They also show about 45 inches of precipitation a year, with no month under 2.75 inches. Our aim is that water moves away and does not collect or freeze under the paving.

What the industry guide says about depth and slope

CMHA’s tech note PAV-TEC-002, Construction of Interlocking Concrete Pavements, gives published minimums that any paver quote can be held against. Patios and other pedestrian areas should have a compacted base at least 4 inches thick over well-drained soil, and the note says that in colder climates, continually wet or weak soils will need a thicker base. The bedding sand above it is screeded to a nominal 1 inch, and the surface should slope at least 1.5 percent.

The same note says geotextile fabric may be used where soil stays saturated for part of the year, where there is freeze and thaw, or over clay and moist silty soils. Those figures are the association’s minimums for concrete pavers, not a specification for your yard. The depth your patio needs depends on the soil and the slope we find at the site, so ask us to write the excavation depth and base thickness into your proposal.

Where the water goes

A patio plan has to say where the rain ends up. We plan slope and drainage so water moves away from the surface, and we look at what else feeds the area: a downspout that discharges beside the patio, a low corner, higher ground next door.

Where slope alone is not enough, drainage is built into the job. Channel drains capture water on the paving, downspout discharge can be routed underground to a safe outlet, and dry wells collect concentrated runoff and disperse it below ground. A drainage plan should never simply move the problem onto the property next door.

Permits and stormwater rules for a patio, township by township

It is often said that a patio at ground level needs no permit. Across the townships we work in, that is not a safe assumption, because most of the rules that touch a patio are stormwater rules, and they are triggered by new hard surface, usually counted in square feet. Here is what each township publishes.

Township	Places it covers	What it publishes for a patio
Tredyffrin (Chester County)	Part of Wayne	Runoff must be controlled on new construction projects over 499 square feet. The application form asks for volume control above 500 square feet and peak rate controls above 1,000. It lists $50 for a residential exemption request and $1,000 per dwelling for a stormwater and grading permit on a detached or twin single-family home.
Upper Merion (Montgomery County)	King of Prussia and part of Wayne	A building permit application with a plot plan showing property line setbacks, plus a Stormwater Class A permit and an impervious surface breakdown, unless the patio is an exact replacement. The 2026 fee schedule lists the Class A permit at $450.
Radnor (Delaware County)	The center of Wayne, and parts of Villanova and Bryn Mawr	An updated stormwater ordinance has applied since October 13, 2022. The township sets out what new hard surface requires on its grading permits page.
Lower Merion (Montgomery County)	Gladwyne, and parts of Villanova and Bryn Mawr	With some exceptions, the stormwater code exempts activity adding 1,500 square feet or less of impervious cover from peak rate control. Recharge or water quality measures can still be required.

Tredyffrin Township

Tredyffrin’s stormwater and grading permits page says residents must control runoff from new construction projects in excess of 499 square feet. Its application form lists Deck/Patio as a type of work. Above 500 square feet the form asks for a site plan and a stormwater management report showing volume control, and above 1,000 square feet it adds peak rate controls.

A grading permit is required for land disturbance of more than 5,000 square feet, or 1,000 square feet on slopes steeper than 15 percent, or whenever stormwater management is required. The township says stormwater, grading and building permit plans can be reviewed at the same time. Where stormwater plans are submitted, the form carries a certification by a design engineer registered in Pennsylvania, and the owner signs that the stormwater facilities are permanent and theirs to maintain.

The fees on the form, updated January 5, 2024, show how much the size line matters. A residential exemption request is $50. A stormwater and grading permit is $1,000 per dwelling for a detached or twin single-family home, and the form lists $2,500 plus $250 per dwelling for attached townhouses. A $3,500 professional services account is added for larger cases, such as plans proposing more than 4,500 square feet of impervious coverage.

Upper Merion Township

Upper Merion’s residential permits page lists two things for a patio. One is a building permit application with a plot plan showing property line setbacks. The other is a Stormwater Class A permit with an impervious surface breakdown, unless the patio is an exact replacement, and the stormwater permit is paid by separate check.

The township’s 2026 building permit fee schedule, adopted April 9, 2026, states that a stormwater permit is required for any new impervious surface or coverage and lists the Class A permit at $450. For patios it shows a building permit fee of $40 for the first $1,000 of estimated construction cost and $30 for each further $1,000 or part of it, and a $125 zoning permit line that names patios and landings. The stormwater part of the schedule also lists a $3,000 professional review escrow, so confirm with the Codes Department which of these apply to your project.

Radnor Township

Radnor Township holds the center of Wayne. Its updated stormwater ordinance took effect on October 13, 2022. A summary from the Suburban Realtors Alliance says the update brought a simplified stormwater management approach and incentives to reduce impervious surface, and notes that Radnor has charged a stormwater management fee on all properties since 2013.

What a new patio needs in Radnor is set out on the township’s grading permits page. Read the current requirements there before the size of the patio is fixed. We tell you what applies to your project before we begin.

Lower Merion Township, and addresses that straddle a line

Gladwyne is in Lower Merion Township. Villanova straddles the border of Lower Merion and Radnor townships, and Bryn Mawr takes in parts of Lower Merion, Haverford and Radnor townships. In either place the first step is to confirm which township your lot is in.

Lower Merion’s stormwater code, with some exceptions, exempts activity that creates 1,500 square feet or less of additional impervious cover from peak rate control, although recharge or water quality standards may still be applied. A civil engineering firm’s page on the township says a drainage system is typically required when a project adds significant impervious surface, usually more than 1,500 square feet. That is an exemption from one requirement, not from a permit, so ask the township what a patio of your size needs. This page does not cover Haverford Township’s rules.

Historic districts in Wayne

Radnor Township has three historic districts: North Wayne, South Wayne and Louella Court. Proposed changes to properties in them go before the township’s Historic and Architectural Review Board. The Radnor Historical Society notes that buildings outside those three districts are not protected simply for being historic. If your home is inside one, ask the township whether a patio, steps or a wall that can be seen from the street needs review before the design is settled.

How a patio project runs

1. The call. Tell us what you have in mind, the town the property is in and how you want to use the space.
2. The site visit. We come to the property and review layout, materials, drainage and site access. This is when you see samples and when we plan the transition from the door to the patio.
3. The estimate. After seeing the space we give you an itemized estimate, with no obligation, and a timeline for your project. We also tell you what the township requires before we begin.
4. The build. Our crew builds the patio, and we keep you updated as the work progresses.
5. The walkthrough. The job ends with a final walk of the finished patio with you.

What happens on build days

Before any digging, Pennsylvania law requires a call to 811. The Public Utility Commission says homeowners and contractors must call at least three business days before starting any digging or excavation, so that buried lines can be marked. A patio means excavation, so the mark-out is part of the schedule.

1. Excavation. The patio area is dug out to the depth the site calls for.
2. Base. Graded aggregate goes in and is compacted, with the slope set so water moves off the surface.
3. Anything that runs under the patio. Conduit for low-voltage lighting and footings for a seating wall or fire feature are placed now, while the base is open.
4. The surface. Pavers or stone are laid to the pattern you chose, with any borders or inlays.
5. Edges and joints. Edge restraints go on and the joints are filled with polymeric jointing material.
6. Finishing. Sealing and finishing complete the surface.

How long this takes depends on the size of the patio, the material, site access and any walls, steps or drainage work involved. We do not publish a standard duration, because there is not one. You get a timeline for your own project with the estimate.

What to have ready for the site visit

• The township your property is in, if you know it.
• Any additions, sheds, driveways or paving added to the lot in recent years. In Tredyffrin the stormwater count is cumulative back to 2009.
• Photos or video of the yard during rain: where water collects and how long it stays.
• How you want to use the space, and whether a fire feature, kitchen, lighting or seating wall may follow later.
• A plot plan or survey, if you have one. Upper Merion asks for a plot plan showing property line setbacks with a patio application.

What a patio installation includes

• A paver or natural stone surface in the material and pattern you chose
• Excavation, a compacted aggregate base, and planned drainage and slope
• Custom shapes, borders and inlays where the design calls for them
• Edge restraints and jointing
• Sealing and finishing

Seating walls, steps, a fire pit, low-voltage lighting and planting around the edges are often planned with the patio. Because we handle hardscaping, outdoor living and lighting ourselves, the patio can be built with the base, conduit and footings already in place for them.

A gas fire feature or an outdoor kitchen needs gas, power or water brought to it. Those routes have to be decided before the patio is laid, so ask at the estimate stage who will run each line.

What a patio costs

We do not publish set prices for patios. Patio pricing depends on size, the material you choose, site access, and how much grading or drainage work the space needs. These are the things that move the figure.

• Size. More area means more excavation, more base and more surface.
• Material. Pavers generally cost less than natural stone.
• Shape and features. A simple, level patio costs less than one with curves, walls, steps or a fire feature.
• Access. How equipment and material reach the back of the property is part of the price.
• Grading and drainage. A yard that needs regrading or drains takes more work to prepare than one that already sheds water.
• Township requirements. Permit fees and any stormwater measures the township asks for are part of the real cost. Tredyffrin’s form lists $50 for a residential exemption request and $1,000 per dwelling for a stormwater and grading permit on a detached or twin single-family home, and Upper Merion’s 2026 schedule lists $450 for a Class A stormwater permit.

After we have seen the space you get an itemized estimate, so there are no surprises and you can see what each element adds. If the full plan is more than you want to build at once, the work can be staged: the patio first, with conduit and footings in place, and the fire feature, kitchen or lighting later.

What to check before you hire a patio contractor

These questions apply to any contractor, and we expect to be asked them too.

• Is the contractor registered with the state? Pennsylvania requires contractors who perform at least $5,000 of home improvements a year to register with the Attorney General’s Office, and the law’s definition of home improvement names patios. The Attorney General’s registration page links to the search where any contractor’s registration can be checked.
• Is the contractor registered with the township? Tredyffrin’s residential permit requirements say all contractors must be registered with the township, and Upper Merion’s fee schedule lists a contractor registration.
• What is in the contract? State law says a home improvement contract must be in writing, be signed by the owner and the contractor, carry the contractor’s registration number, give approximate start and completion dates, describe the work, the materials and a set of specifications, and state the total price.
• What cover does the contract state? The same law has the contractor agree in the contract to maintain liability insurance of at least $50,000 for personal injury and $50,000 for property damage.
• Can you change your mind? You may cancel without penalty within three business days of signing.
• How much is the deposit? On a contract of more than $5,000, a contractor may not take a deposit above one third of the price, plus the cost of special order materials.
• How deep is the base? Get the excavation depth, base thickness and jointing material into the written specifications.
• Where does the water go? Ask for the direction of slope and any drains to be shown on the plan.
• Who deals with the township? Ask who prepares the plot plan, who submits the application and whether permit fees are in the price.
• What happens if something settles? Ask who comes back, and for how long, and get the answer in writing.
• Whose work is in the photos? Ask to see patios the contractor built, and ask what was put under them.

How the patio ties into the rest of the yard

A patio rarely stands alone for long. It flows into a walkway, a seating wall frames the fire pit, and the whole area should read as one finished space. This page covers the patio itself, and the pages below own the work around it.

Page	What it covers	Start there if
Outdoor living contractor Wayne	Fire pits and fireplaces, outdoor kitchens, seating walls and lighting, planned as one outdoor room	The patio is the floor for something bigger
Retaining wall contractor Wayne	Retaining walls, tiered terraces and seating walls, with their base and drainage	The yard slopes and level ground has to be made
Backyard renovation Wayne	A full redesign of an existing yard	More than one part of the yard is changing
Landscape design build Wayne	One plan for the whole property: paving, planting, grading, drainage and lighting	You want the whole property designed before anything is built

Planting is the other half of a patio. Beds along the edges are easier to plan before the base is dug than after, and we design them with the paving. For who we are and how we work, see about.

Where we install patios

We install patios in Wayne, Radnor, Villanova, Bryn Mawr, Gladwyne and King of Prussia. Those places sit in several townships, including Radnor, Tredyffrin, Upper Merion and Lower Merion, and the township decides the rules for new paving. If your property is in another Main Line town, call us and ask.

Questions people ask