Pavilion on Existing Slab — Panama City, Florida

Project Type: Residential Pavilion / Covered Outdoor Structure
Location: Panama City, Florida
Scope: Structural permit drawings + Florida PE review coordination
Existing Condition: Existing concrete slab to remain and be evaluated as part of the proposed pavilion scope
Project Status: Drawing and engineering coordination case study
Primary Services: Structural permit drawings, existing-slab coordination, foundation review, Florida PE review, permit drawing preparation

A homeowner in Panama City, Florida wanted to construct a new pavilion over an existing concrete slab rather than demolish the slab and pour a completely new foundation.

The key design question was not simply:

“Can we put a pavilion on this slab?”

The real permit and engineering issue was whether the existing slab and perimeter foundation conditions could be properly documented and coordinated with the loads from the proposed pavilion.

Site Plans FL prepared the project around the existing conditions, pavilion structural requirements and Florida PE review process.

Florida Structural Permit Drawings

Florida PE Stamp & Engineering Review

Project Overview

The project involved a proposed pavilion to be supported on an existing concrete slab measuring approximately:

24′-0″ × 14′-0″

Available information indicated:

• Existing concrete slab
• Approximate slab footprint: 24 ft × 14 ft
• Existing perimeter footing approximately 12 in. × 10 in.
• Existing corner foundation areas approximately 20 in. × 20 in. × 10 in.
• Proposed pavilion structure above the existing slab
• Structural and foundation coordination required
• Florida PE review requested for the structural permit package

The design intent was to preserve the existing concrete where practical rather than automatically demolishing it.

The Main Challenge

Using an Existing Slab for a New Pavilion

An existing slab cannot automatically be assumed to support a new pavilion simply because it appears to be in good condition.

A pavilion introduces structural forces that may include:

• Gravity loads
• Roof dead load
• Roof live load
• Wind pressure
• Wind uplift
• Post reactions
• Lateral forces
• Overturning
• Anchor forces
• Concentrated footing loads

The structural load path runs from:

Roof → Rafters / Framing → Beams → Posts → Connections → Foundation → Soil

The existing concrete therefore had to be considered as part of the complete structural system.

Existing Concrete Conditions

The available project information showed an existing concrete pad approximately:

24′-0″ wide × 14′-0″ deep

Foundation information available for coordination included:

Perimeter Footing

Approximately:

12″ wide × 10″ deep

Corner Foundation Areas

Approximately:

20″ × 20″ × 10″

These dimensions became important because pavilion posts can create concentrated loads that differ significantly from loads associated with a simple patio slab.

The existing slab therefore needed to be coordinated with:

• Proposed post locations
• Post reactions
• Anchor locations
• Foundation capacity
• Wind uplift
• Pavilion framing geometry

Why an Existing Slab Requires Engineering Review

A patio slab and a pavilion foundation do not necessarily perform the same structural function.

A typical slab may have been constructed primarily to support:

• Pedestrian loads
• Patio furniture
• Minor distributed loads

A pavilion can impose concentrated forces at individual posts.

Those forces may include both:

Downward Compression

and

Upward Wind Forces

For this reason, the structural review may need to consider:

• Concrete thickness
• Footing geometry
• Reinforcement information
• Concrete condition
• Post locations
• Anchor embedment
• Edge distances
• Wind loads
• Soil assumptions
• Existing construction documentation

If sufficient information about an existing slab is unavailable, additional verification may be required before an engineer can accept the existing foundation for a new structural load.

Proposed Pavilion Structural Scope

The structural drawing package was organized around the proposed pavilion and existing foundation.

Potential structural information included:

• Pavilion overall dimensions
• Post layout
• Beam layout
• Roof framing
• Roof slope
• Framing member sizes
• Structural connections
• Post-to-beam connections
• Post bases
• Anchoring
• Foundation / existing slab coordination
• General structural notes
• Design criteria
• Florida PE review

The intent was to produce a clear permit drawing package rather than a conceptual sketch.

Pavilion Post Layout

Post Locations Matter

The pavilion posts are among the most important components when an existing slab is being reused.

The posts transfer roof loads into the foundation.

The drawing therefore needs to clearly coordinate:

• Number of posts
• Post dimensions
• Post spacing
• Relationship to slab edges
• Relationship to existing perimeter footing
• Relationship to corner foundation areas
• Beam support
• Anchor locations

Poor post placement could result in pavilion reactions occurring over portions of the slab that were not originally intended to receive concentrated structural loads.

Beam & Roof Framing Coordination

The pavilion framing system also needed to provide a continuous load path.

The drawings may identify:

• Main beams
• Roof rafters
• Roof framing spacing
• Roof sheathing or panel system
• Connections
• Beam bearing
• Rafter-to-beam connections
• Post-to-beam connections
• Uplift connectors

Structural framing dimensions should match the final architectural/pavilion geometry.

Wind Design Considerations

Florida outdoor structures require careful attention to wind.

Open-sided pavilions can experience substantial wind uplift because wind can act both above and below the roof surface.

Potential engineering considerations include:

• Project location
• Applicable design wind speed
• Exposure
• Risk category
• Roof geometry
• Roof slope
• Effective wind area
• Uplift pressures
• Post reactions
• Connection forces
• Anchor forces
• Overturning

A strong roof member alone is not enough.

The entire structural load path must work together.

Structural Load Path

The project was coordinated around a clear structural load path:

Roof Covering

↓

Roof Framing

↓

Beams

↓

Posts

↓

Post Bases / Anchors

↓

Existing Foundation / Concrete

↓

Supporting Soil

Every connection in that sequence matters.

A permit drawing should make the load transfer understandable to both the engineer and permit reviewer.

Existing Slab vs New Foundation

Option 1 — Use Existing Slab / Foundation

If the engineer determines that the existing conditions are suitable for the pavilion loads, the project may be able to retain the existing concrete.

Possible benefits include:

• Less demolition
• Lower construction disturbance
• Reduced material waste
• Faster construction
• Lower foundation cost

However, suitability must be based on engineering review and available verification.

Option 2 — Add New Localized Footings

If the existing slab alone is not sufficient, localized structural footings may potentially be designed beneath pavilion posts.

This approach can preserve much of the existing slab while adding structural support where concentrated loads occur.

Option 3 — Replace / Modify Foundation

Where existing conditions are inadequate or unknown, larger foundation modifications may be required.

The engineer determines the appropriate approach based on the actual project information.

What Was Important to Document

For this type of pavilion project, the permit drawings should clearly document the relationship between the new structure and the existing foundation.

Important information may include:

• Existing slab dimensions
• Existing footing dimensions
• Proposed post locations
• Anchor requirements
• Beam sizes
• Roof framing
• Roof slope
• Connection hardware
• Wind design criteria
• Foundation assumptions
• Existing-condition notes
• Structural details

This minimizes ambiguity during permit review and construction.

Permit Drawing Package

The pavilion structural package may include sheets such as:

Cover / Structural General Notes

Project information, scope, code references, design criteria and general structural requirements.

Pavilion Framing Plan

Overall geometry, posts, beams and framing.

Roof Framing Plan

Rafter layout, spacing, beam relationships and roof framing notes.

Foundation / Existing Slab Plan

Existing slab footprint, proposed post locations, foundation coordination and anchor conditions.

Structural Sections

Vertical relationships between roof, beams, posts and foundation.

Connection Details

Typical post-to-beam, rafter-to-beam and base-anchor details.

Engineering Notes / Calculations

Where included within the engineer’s scope.

Florida PE Review Coordination

The project included coordination for Florida Professional Engineer review.

A PE review is not simply adding a seal graphic to a completed drawing.

The engineer must be able to review and accept responsibility for the engineering within their professional scope.

During the review process, the engineer may request:

• Revised member sizes
• Additional reinforcement
• Larger footing
• Different anchorage
• Additional connections
• Additional dimensions
• Existing slab verification
• Concrete information
• Additional project photos
• Field verification

The drawing set can then be revised as needed before final signed/sealed documents are issued.

Learn About Florida PE Review

What We Need for an Existing-Slab Pavilion Project

If you are planning a similar project, start by sending:

Property Address

This helps identify the project jurisdiction and applicable site conditions.

Existing Slab Dimensions

Length, width and thickness if known.

Foundation Information

Provide any known:

• Footing dimensions
• Reinforcement
• Edge thickening
• Corner pads
• Existing construction drawings

Photos

Send clear photos of:

• Entire slab
• Slab edges
• Corners
• Cracking
• Existing anchors
• Surrounding grade
• Adjacent structures

Pavilion Dimensions

Overall:

• Length
• Width
• Height
• Roof slope

Pavilion Manufacturer Information

If using a prefabricated system, provide:

• Manufacturer drawings
• Post reactions
• Anchor requirements
• Roof system
• Structural specifications

Permit Comments

If the project has already been submitted, provide the entire correction notice.

What If Existing Foundation Information Is Unknown?

This is common with older slabs.

If there are no original construction drawings, engineering may require additional verification.

Possible methods may include:

• Contractor measurements
• Exposed-edge measurement
• Test openings
• Concrete scanning
• Reinforcement verification
• Field inspection
• Other investigation requested by the engineer

Site Plans FL does not recommend presenting unknown structural conditions as verified facts.

The engineering review should distinguish between:

Documented Existing Conditions

and

Assumed Conditions Requiring Verification

Remote Drafting & Coordination

Many pavilion projects can begin remotely.

Useful information includes:

• Property address
• Survey
• Photos
• Existing slab dimensions
• Pavilion layout
• Manufacturer documents
• Contractor measurements
• Permit comments

However, where structural conditions must be physically verified, field investigation may still be necessary.

Remote drafting does not replace an inspection where an engineer or reviewing authority requires one.

Project Outcome

The project was developed as a pavilion structural permit package using the existing concrete slab as the starting foundation condition, with structural and Florida PE review coordination included in the agreed scope.

The primary value of the design process was ensuring that the project was not treated as simply:

“Place pavilion posts on existing concrete.”

Instead, the drawings coordinated:

• Existing foundation geometry
• Pavilion post locations
• Roof framing
• Structural load path
• Connections
• Anchoring
• Wind considerations
• Engineering review

This creates a much stronger permit and construction package.

Important: This case study describes the drawing and engineering coordination scope. It should not be interpreted as a guarantee of permit approval or as a statement that every existing slab can support a new pavilion.

Similar Projects We Can Help With

Site Plans FL can assist with permit drawing and engineering coordination for:

• Pavilions
• Pergolas
• Patio covers
• Covered porches
• Carports
• Breezeways
• Deck roofs
• Outdoor kitchens with structural roofs
• Pool-side structures
• Existing-slab metal buildings
• Garages on existing slabs
• Accessory structures

Residential Site Plans & Permit Drawings

Florida Structural Permit Drawings

Florida PE Stamp & Engineering Review

Florida Permit Corrections

Florida Metal Building Permit Drawings

Related Florida Project Case Studies

Site Plans FL has worked on a range of residential and commercial permit projects across Florida.

Elevated Waterfront Residence — Hernando Beach, Florida

Flood-zone residential permit package involving elevated construction, structural coordination, MEP and engineering.

View Case Study

Commercial Change of Use — Doral, Florida

Commercial warehouse project involving change-of-use, accessibility, occupancy, MEP and permit coordination.

View Case Study

After-the-Fact Shed Legalization — Miami, Florida

Existing accessory structure legalization involving site planning, setbacks and lot-coverage documentation.

View Case Study

Screened Porch / Greenspace Coordination — Tampa, Florida

Residential permit correction project involving greenspace, lot coverage, tree protection, grading and drainage.

View Case Study

View All Florida Case Studies

Frequently Asked Questions

Can I build a pavilion on an existing concrete slab?

Potentially, but the existing slab and foundation must be suitable for the new structural loads.

The engineer may need information about slab thickness, footings, reinforcement, post locations, anchors and existing concrete condition before accepting it.

Is a 4-inch patio slab enough for a pavilion?

Slab thickness alone does not determine whether an existing slab is adequate.

Pavilion posts can create concentrated vertical and uplift loads. Footings or thickened foundation areas may also be required.

Do pavilion posts need separate footings?

They may.

The requirement depends on the pavilion loads, slab/foundation configuration, soil assumptions, wind loads and engineering design.

Can new footings be added without removing the entire slab?

Sometimes localized footings can be designed at post locations while retaining much of the existing slab.

The appropriate solution depends on the actual structural conditions.

Does a pavilion need a permit in Florida?

Permit requirements depend on the jurisdiction, structure size and project conditions. A structural outdoor roof structure commonly requires permit documentation.

Always confirm the requirements for the exact property address.

Does a pavilion need a Florida PE stamp?

Not every pavilion automatically requires PE engineering, but structural engineering may be required based on the design, spans, wind loads, connections, foundation or reviewing authority.

Do you provide pavilion structural drawings?

Yes.

Potential scope can include:

• Framing plan
• roof framing
• posts
• beams
• footings
• connections
• anchorage
• structural details

Can you review an existing slab remotely?

Drafting and preliminary engineering coordination can often begin remotely using photos, measurements and existing documentation.

However, physical verification may be necessary where important structural conditions are unknown.

What happens if the engineer says the existing slab is insufficient?

The plans may need to be revised to add:

• New footings
• larger foundation areas
• reinforcement
• different post locations
• revised anchors

The final solution depends on engineering review.

Can you prepare plans if I already purchased the pavilion?

Yes.

Send:

• Manufacturer drawings
• Overall dimensions
• Post locations
• Reactions if available
• Anchor specifications
• Property address
• Existing slab information

We can review the permit drawing scope.

Can you help if my pavilion permit received corrections?

Yes.

Send the complete correction notice and the exact submitted drawing package.

Permit Corrections & Resubmittals

Do you guarantee permit approval?

No.

Permit approval is determined by the reviewing authority.

Our role is to prepare and coordinate drawings within the agreed project scope and assist with applicable corrections.

Need Permit Plans for a Pavilion on an Existing Slab?

Send us:

Property Address

Existing Slab Dimensions

Photos

Pavilion Dimensions

Manufacturer Drawings, if applicable

Permit Comments, if already submitted

We can review whether the project needs:

• Site plan
• Structural drawings
• Foundation coordination
• Existing slab review
• Wind / anchorage engineering
• Florida PE review
• Permit corrections

Request a Pavilion Project Review

Phone / WhatsApp: +1 (385) 885-5362
Email: drafting@siteplansfl.com