Whole-home application map

Where spray foam may fit.

Start with the surface and the job it performs. Twenty-three locations cover homes, foundations, roofs, workshops, vehicles, compact structures, and wet zones without treating them as one generic cavity.

01Enclosure boundary

Between conditioned space and outdoors, soil, or an unconditioned space.

02Interior partition

Between rooms, often for privacy or sound rather than thermal performance.

03Special boundary

A garage, rated separation, equipment area, or another condition with added duties.

04Local connection

An opening, joint, or service interface that needs a targeted and repairable closure.

1Name both sides

Outdoors, soil, attic, garage, crawl space, or another conditioned room?

2Find the real problem

Heat, air, water, sound, vibration, or a local gap?

3Check access

Open framing, one-sided access, a finished cavity, or exterior work?

4Verify the system

Exact product, approved use, protective finish, and inspection plan.

Explore by location

Choose the assembly before the material.

Filters help you narrow the map. They do not mean every listed location should use spray foam.

Showing all 23 areas

01Enclosure boundary

Above the top-story ceiling

Attic floor

Keep a vented attic outside the conditioned enclosure by aligning ceiling air control and insulation.

Check first
Roof leaks, recessed fixtures, flues, attic access, ducts, and the existing ceiling air barrier.
Access reality
Open attic access; ceiling penetrations still need inspection.
Open the project guide
02Enclosure boundary

Following the sloped roof

Roof deck or roofline

An unvented roofline changes the enclosure and can change conditions around sheathing, ducts, and equipment.

Check first
Roof condition, current vent path, sheathing, climate, combustion equipment, and the complete moisture design.
Access reality
From the attic, room side, or above during reroofing, depending on the assembly.
Open the project guide
03Enclosure boundary

Around conditioned living space

Exterior walls

Wall insulation has to work with cladding, drainage, sheathing, air control, vapor control, and drying.

Check first
Whether the cavity is open, the rain-control path works, and existing layers can be identified.
Access reality
Open framing is easier to verify; finished-wall injection is a different method and scope.
Open the project guide
04Interior partition

Between rooms inside the home

Interior walls

A partition between conditioned rooms usually has no exterior thermal duty. Sound, privacy, and service access may still matter.

Check first
The actual sound or air path, both room uses, doors, ceiling bypasses, plumbing, wiring, and wall rating.
Access reality
Open walls allow full assembly choices; closed cavities require a documented retrofit method.
Open the project guide
05Local connection

Where the floor framing meets the foundation

Rim joists

The visible rim cavity is only part of a perimeter connection that may include sill, masonry, framing, and services.

Check first
Staining, wood condition, sill and masonry joints, pests, service penetrations, and required inspection access.
Access reality
Often visible from a basement or crawl space; finished ceilings can hide the connection.
Open the project guide
06Enclosure boundary

At below-grade foundation walls

Basement walls

Interior insulation belongs after the source of water, dampness, efflorescence, or wall damage is investigated.

Check first
Bulk water, capillary moisture, cracks, grading, drainage, radon planning, and foundation condition.
Access reality
Best evaluated before interior framing and finishes conceal the foundation.
Open the project guide
07Enclosure boundary

At the floor above or the crawl-space perimeter

Crawl spaces

Choose whether the boundary follows the floor or foundation walls, then coordinate ground moisture and water management.

Check first
Standing water, ground vapor control, drainage, wood condition, pests, ducts, equipment, and vent strategy.
Access reality
Limited height and contaminated or unsafe conditions can make this a professional scope.
Open the project guide
08Special boundary

Between garage air and occupied rooms

Attached garages and floors above

This boundary manages heat and air while preserving pollutant separation, fire protection, and safe equipment conditions.

Check first
Shared walls and ceilings, open joist paths, penetrations, ducts, connecting doors, equipment, and local fire requirements.
Access reality
Open framing is preferred; a finished garage ceiling may need planned investigation and repair.
Open the project guide
09Enclosure boundary

Beside small attic spaces

Knee walls and bonus rooms

The boundary can run around the room or follow the main roofline. Floor, wall, roof, and access-panel transitions must connect.

Check first
Which spaces are inside, whether side attics are vented, and how the wall connects to the floor and roof.
Access reality
Side-attic access can help, but narrow eaves and hidden floor cavities remain difficult.
Open the project guide
10Local connection

At local joints and penetrations

Windows, doors, and small gaps

Small air-sealing products have defined joint sizes, movement limits, substrates, and locations. Exterior drainage remains separate.

Check first
Where the leak path is, how water drains, whether the opening moves, and which exact product permits the joint.
Access reality
Trim removal or an open rough opening may reveal more than a surface bead can address.
Open the project guide
11Local connection

Where wiring, pipe, sleeves, ducts, and flues cross assemblies

Service penetrations

The service, assembly, opening, movement, heat, fire role, and future access determine the closure.

Check first
Service identity, damaged or active systems, rated construction, hot surfaces, opening support, and exact compatibility.
Access reality
Keep boxes, valves, connectors, cleanouts, fasteners, and required inspection points accessible.
Open the project guide
12Enclosure boundary

Above outdoor air, vented crawl spaces, garages, or open piers

Floors over unconditioned space

Floor insulation must connect at joists, rims, supports, cantilevers, chases, and exterior walls.

Check first
What lies below, bulk water, floor condition, ducts, pipes, wiring, pests, and perimeter continuity.
Access reality
Open framing permits full inspection; ceilings and belly materials can hide services and boundary breaks.
Open the project guide
13Interior partition

Between stories, rooms, chases, garages, and special-use spaces

Interior floors and ceilings

Separate sound, services, radiant heat, garage separation, rated assemblies, and true thermal boundaries.

Check first
The primary job, flanking paths, recessed fixtures, ducts, pipes, wiring, framing, and complete tested assembly.
Access reality
Inspect from above and below before finishes hide service routes and required layer continuity.
Open the project guide
14Special boundary

At ducts, air handlers, equipment rooms, drains, and controls

HVAC and mechanical systems

Duct sealing, insulation, encapsulation, enclosure work, equipment safety, and commissioning remain distinct scopes.

Check first
Duct leakage and condition, condensation, equipment, flues, intakes, drains, filters, controls, and service clearance.
Access reality
Preserve panels, filters, drains, dampers, sensors, joints, and replacement paths after enclosure work.
Open the project guide
15Enclosure boundary

At metal roofs, walls, girts, purlins, posts, and panel joints

Metal buildings and pole barns

Panel temperature, indoor humidity, coatings, movement, corrosion, use, and replaceability shape the system.

Check first
Occupancy, water entry, panel coating, corrosion, condensation plan, ignition sources, and protective finish.
Access reality
Photograph every panel and service; bonded foam can change later fastener, welding, and replacement work.
Open the project guide
16Special boundary

In accessory buildings used for storage, vehicles, hobbies, or daily work

Sheds, workshops, and detached garages

The present and future use controls moisture, ventilation, fire, impact, equipment, and finish requirements.

Check first
Use, stored materials, fuels, dust, fumes, vehicles, water, electrical work, heating, and source exhaust.
Access reality
Mark services and use durable removable finishes where tools, equipment, and future changes are expected.
Open the project guide
17Special boundary

Inside moving shells with dense utilities and repair seams

Vans, trailers, and RVs

Movement, vibration, corrosion, drains, wiring, fuels, ventilation, weight, and service access replace house assumptions.

Check first
Vehicle classification, ratings, leak and corrosion history, coatings, seams, drains, utilities, and operating modes.
Access reality
Keep connectors, drains, fasteners, modules, appliances, labels, and repair-prone seams reachable.
Open the project guide
18Special boundary

In compact structures with different legal and structural systems

Manufactured homes, tiny houses, and containers

Classify the unit first, then address labels, transport, thin assemblies, steel bridges, utilities, and occupancy moisture.

Check first
Data plates, certification, jurisdiction, structural changes, transport status, leaks, corrosion, and utility map.
Access reality
Do not obscure required labels or close dense service zones without an as-built access and repair plan.
Open the project guide
19Special boundary

At wet-zone shells, cabinets, equipment, plumbing, walls, and landscape details

Pools, spas, and water features

Decorative filling, cabinet insulation, building enclosure work, and pool systems require different evidence.

Check first
Exact component, water contact, liner or shell, drainage, chemistry, heat, sunlight, electricity, and service.
Access reality
Keep bonding, wiring, pumps, drains, valves, unions, labels, filters, and winterization points usable.
Open the project guide
20Enclosure boundary

Outside basement or crawl-space foundations before backfill

Exterior below-grade walls

Foundation repair, waterproofing, drainage, insulation, protection, termites, and transitions form one buried system.

Check first
Structure, cracks, runoff, grade, groundwater, footing drains, discharge, leakage, and pest requirements.
Access reality
Inspect and photograph every layer before backfill; record buried utilities, drains, repairs, and terminations.
Open the project guide
21Enclosure boundary

Between prepared ground layers and a concrete slab

Below-slab insulation

Loads, base preparation, water, vapor, radon, utilities, slab edges, concrete work, and product properties must align.

Check first
Slab use and loads, soil and groundwater, drainage, vapor plan, radon, termites, utilities, and edge details.
Access reality
Use a signed pre-pour hold point; most of the assembly cannot be inspected or repaired after concrete placement.
Open the project guide
22Enclosure boundary

On the exterior of low-slope roofs as a foam and coating system

Spray polyurethane foam roofing

Exterior SPF roofing combines substrate, drainage, foam, coating, details, quality control, repair, and maintenance.

Check first
Existing roof moisture and attachment, deck, slope, drains, penetrations, edges, contamination, traffic, and weather.
Access reality
Plan walkways, drains, equipment service, inspection, compatible repair, and periodic recoating from the start.
Open the project guide
23Enclosure boundary

Outside sheathing within a continuous insulation and recladding project

Exterior wall spray foam and coatings

Exterior spray layers change drainage, openings, attachments, movement, fire exposure, protection, and repair.

Check first
Existing wall layers and damage, opening flashing, water path, attachment loads, compatibility, and fire evidence.
Access reality
Inspect by elevation before cladding; retain opening, fastening, coating, sealant, and maintenance details.
Open the project guide

Four location types

What the material cannot decide for you.

Commercial application lists can make unlike projects look interchangeable. These checks stay attached to every route through our map.

01

It does not repair a water source.

Roof, wall, foundation, and plumbing water need diagnosis and repair before concealment.

02

It does not soundproof a room by itself.

Complete partitions, doors, ceilings, framing, penetrations, and flanking paths determine the result.

03

It does not replace an approved assembly.

Fire protection, product approvals, ventilation, clearances, and local inspection remain separate requirements.

Complete application core

Every special use now has a bounded guide.

The map keeps house cavities, ducts, metal buildings, vehicles, wet zones, roofing, exterior coatings, and below-grade work in separate evidence paths. Each route begins with the assembly and stop conditions before it discusses products.

Learn how to verify product documents

Common questions

Use the map without turning it into a blanket approval.

Can spray foam be used in interior walls?

It may be considered for a documented interior-wall assembly, but a partition between conditioned rooms usually is not part of the thermal enclosure. Define the sound, privacy, air-control, fire, or special-use goal and compare complete wall systems before selecting a material.

Can the same spray foam be used everywhere in a home?

No universal product or method fits every location. Product format, approved use, substrate, access, moisture design, installed thickness, exposure controls, and required protective construction change by application.

Should a homeowner start with a product or a location?

Start with the building location and the role of the assembly. Identify water, air, heat, vapor, sound, fire, access, and service conditions. Then compare materials and exact products that document the intended use.