How To Look At A House

McGarry and Madsen's home inspection blog for buyers of  

site-built, mobile/manfuactured and modular homes

What is the purpose of the gravel on a flat tar roof?

Friday, July 6, 2018

Gravel provides shade to the top layer of asphalt tar, protecting it from the ultraviolet rays in sunlight. UV rays speed up asphalt deterioration and cracking when the asphalt is directly exposed to sunlight. 


    Next time you are close-up to an asphalt roof shingle roof, notice that they also have a coating of rock, but it is finely ground granules and serves the same protective purpose. When a shingle roof loses its tiny rock coating, as in the photo below, it means the roof is at the end of its lifespan and the shingles are brittle.


    A secondary benefit of the layer of rock embedded in the top flood coat of asphalt is that the white or light tan color reflects the suns rays, keeping the roof cooler. Heat is factor another that accelerates the deterioration of a roof surface. Also, the weight of the gravel helps keeps the roof secured in place.

• • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 

Here’s links to some of our other articles about “FLAT ROOFS (LOW SLOPE)":

Do flat roofs always leak?

What causes bubble-like blisters in a built-up and gravel roof?  

Why does it cost so much more to replace a steep roof than a low slope roof? 

Why are most house roofs slanted instead of flat?

What is "ponding" on a flat roof?

Why is there no attic access hatch in the house?

What is the difference between roll roofing and modified bitumen? 

 What is the purpose of the gravel on a flat tar roof? 

Can metal roofing be used on a low slope/pitch roof? 

What is a TPO roof? 

What is the stuff you paint an old mobile home metal roof with to extend its life?

Does a gravel roof need maintenance?

What is the average lifespan of a built-up and gravel roof?

What is the average lifespan of a modified bitumen roof? 

What is the average life expectancy of a TPO (Thermoplastic PolyOlefin) roof? 

What is an EPDM roof?

• What is the average life expectancy an EPDM roof? 

 I'm buying a '50s modern house with a "gravel" roof. Is the roof going to be a problem? 

Is "ponding" (standing puddles of water) normal on flat roof?

What is a low slope roof?

• What is the average life expectancy of a built-up roof? 

What is the average life expectancy of an elastomeric roof coating?

 • Can you coat a TPO roof to extend its life? 

What causes ponding (standing water) on a flat roof?

• What are the signs my flat roof needs to be replaced? 

What is the average life expectancy of a PVC roof?

    Visit our ROOF AND ATTIC page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.

Water Heaters

Water Heater Age

"What Are The

Signs Of..."

Septic Tank Systems

Structure and Rooms

Plumbing Pipes

Termites, Wood Rot

& Pests

Sinkholes

Stairs

When It First

Became Code

"Should I Buy A..."

Park Model Homes

Site

Shingle Roofs

Safety

Stucco

Remodeling

Wind Mitigation

Roof and Attic

"Does A Home

Inspector...?"

Pool and Spa

"What Is The Difference Between..."

Radon

Brick

Plumbing

Concrete and

Concrete Block

Metal Roofs

Foundations

Modular Homes

Rain Gutters

Mold, Lead & Other Contaminants

Condominiums

Older and

Historic Houses

Crawl Spaces

Mobile-Manufactured Homes

Building Permits

Life Expectancy

Clay Soil

Insurance

Floors

Insulation

Toilets

Exterior Walls

& Structures

Generators

Common Problems

HUD-Code for

Mobile Homes

Garages and Carports

Flat (Low Slope) Roofs

Electrical Panels

Sprinkler Systems

Electrical Receptacle Outlets

4-Point Inspections

Hurricane Resistance

Frequently Asked Questions (FAQ)

Home Inspection

Heating and Air Conditioning

Building Codes

Fireplaces and Chimneys

Inspector Licensing

& Standards

Energy Efficiency

Washers and Dryers

Electrical

Kitchens

Doors and Windows

(placeholder)

Cracks

Electrical Wiring

Click Below  

for Links

to Collections

of Blog Posts

by Subject

Plumbing Drains

and Traps

Appliances

Smoke & CO Alarms

Aging in Place

Top 5 results given instantly.

Click on magnifying glass

for all search results.

Bathrooms

Lighting

AFCI, CAFCI,

DFCI, & GFCI

Sinks

Air Conditioner & Furnace Age/Size

Attics

Electrical Switches

Siding

Search

This

Site

Water Intrusion

Electrical - Old

and Obsolete

(placeholder)

Foundation Certifications

Tiny Houses

About Us

(placeholder)

Wells