Rolled roofing is the fastest and most budget-friendly solution for waterproofing low-slope structures like sheds, garages, and porches. This material, often called MSR or mineral-surfaced roofing, is designed specifically to stop leaks without the high cost of hiring a professional contractor. While many homeowners avoid roofing projects because they fear dangerous torches or complex machinery, this installation is actually a safe and simple weekend task. It utilizes a beginner-friendly “cold process” that requires only standard roofing nails and cement to create a watertight seal. This guide breaks down exactly how to secure your property against the rain in just one afternoon using tools you likely already own.
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Benefits of Installing Rolled Roofing
Rolled roofing (also known as mineral surfaced roofing or MSR) is the primary choice for homeowners covering low-slope structures like sheds, garages, and porches. It is specifically designed for roofs where standard shingles won’t work because the pitch is too flat.
Why it is the top choice for DIY projects:
- Most Affordable Option: Rolled roofing is widely considered the cheapest roofing material available per square foot, making it perfect for budget renovations.
- Fast Installation: You can cover large areas in minutes. Instead of nailing down hundreds of individual shingles, you simply unroll, cut, and secure large sheets.
- No Special Equipment: This material uses a “cold process” installation. You only need a hammer, utility knife, and roofing cement – no dangerous torches or hot tar are required.
- Easy Transport: The material comes in compact 100-square-foot rolls that fit easily into the back of a standard car or SUV, saving you money on delivery fees.
What You Will Need
To avoid stopping halfway through to run back to the store, gather these supplies first.
Essential Materials:
- Rolled Roofing (MSR): Measure your roof and buy 10% extra for waste.
- Roofing Felt (Tar Paper): This acts as a base layer.
- Galvanized Roofing Nails: Look for 11 or 12-gauge nails with wide heads.
- Roofing Cement: You will need tubes for a caulking gun and a tub for troweling.
- Metal Drip Edge: To protect the edges of the roof deck.
Required Tools:
- Utility knife with hook blades (standard blades dull too fast).
- Hammer.
- Tape measure and chalk line.
- Trowel.
- Broom or leaf blower.
Step 1: Prepare the Roof Deck
The most important part of roofing happens before you lay the first roll. If your roof surface is dirty or wet, the new roofing won’t stick, and it will eventually rot.
Start by removing all old roofing material down to the bare wood sheathing. Pull out any old nails and sweep the deck clean. If you see any rotted wood or soft spots, you must replace those plywood sections now. Installing new roofing over rotten wood is a waste of time and money.
Once the wood is clean and solid, install your metal drip edge along the eaves (the bottom edges of the roof). This metal strip helps water flow off the roof without curling back underneath the wood.
Step 2: Install the Underlayment
Think of the underlayment as a backup safety layer. Roll out your roofing felt (tar paper) over the bare wood. Start at the bottom and work your way up.
Smooth it out to remove wrinkles and secure it with staples or a few roofing nails. If you need multiple rows of paper, make sure the top row overlaps the bottom row by at least 2 inches. This ensures that if water gets past the top layer, it flows over the paper and not under it.
Step 3: Lay the First Sheet of Roofing
Now you are ready for the actual rolled roofing.
Cut your first sheet to the length of the roof. It is a great idea to unroll the material and let it sit in the sun for about 20 minutes before nailing it down. This warms up the asphalt, making it flat, flexible, and much easier to handle.
Position this first sheet at the lowest edge of the roof. It should overhang the edge by about a 1/4 inch. Nail it down securely, placing a nail every 6 to 12 inches along the edges.
Step 4: Seal and Overlap the Seams
This is the step where leaks are prevented. When you install the second sheet, you must create a watertight seal where it meets the first sheet.
- Position the Sheet: Place the second sheet so it overlaps the first sheet by at least 2 to 4 inches. Most rolled roofing has a “selvage edge” (a line) that shows you exactly where to overlap.
- Apply Cement: Before you nail it, lift the edge of the new sheet. Use your trowel to spread a generous layer of roofing cement all along the overlap area. This glue is the primary barrier against water.
- Press and Nail: Press the sheet down firmly into the wet cement. Then, drive nails through the overlapped area to lock it in place.
Repeat this process, working your way up to the peak of the roof. Always remember the “shingle effect”: the upper sheet must always sit on top of the lower sheet so water runs down over the seam.
Step 5: Finish the Edges
Once the main roof area is covered, you need to seal the sides (called the rakes).
Install metal drip edge over the roofing material on the sides. Nail it down, and then cover those nail heads with a dab of roofing cement. Finally, inspect the entire roof. If you see any exposed nail heads or loose edges, cover them with a small amount of cement to make them watertight.
Conclusion
Mastering the installation of rolled roofing gives you a cost-effective way to protect your home’s smaller structures. By strictly following the “cold process” and ensuring every seam is sealed with cement, you can achieve a durable result that rivals professional work.
Industry leaders like Core Commercial Roofing & Coatings emphasize that the secret to a long-lasting roof lies in preparation specifically, ensuring the deck is clean and the temperature is right before you start. Whether you are tackling a backyard shed or a larger garage, adhering to these professional standards ensures your roof will handle the elements for years to come. Do you have the measurements of your roof handy? If you paste them here (length and width), I can calculate exactly how many rolls of roofing and felt paper you need to buy so you don’t overspend.
FAQs
How much should I overlap rolled roofing sheets?
You must overlap the sheets by at least 2 to 4 inches, or follow the specific “selvage edge” line printed on the roll by the manufacturer. It is critical to apply a continuous, generous layer of roofing cement between these layers to create a watertight bond. Experts at Core Commercial Roofing & Coatings emphasize that skimping on this adhesive step is the leading cause of seam failure in DIY flat roof projects.
What is the minimum temperature for installing rolled roofing?
You should never install rolled roofing when the temperature is below 45°F (7°C) because the asphalt becomes brittle and will crack when you try to unroll it. For the best results, pick a warm, sunny day and let the unrolled sheets sit in the sun for 20 minutes to relax and flatten out before you begin nailing.
Can I install rolled roofing over old shingles?
It is highly recommended to remove all existing roofing down to the bare wood deck rather than layering over old shingles. An uneven surface can puncture the new material and prevent the seams from sealing flat against the roof. Core Commercial Roofing & Coatings advises starting with a clean, dry plywood surface to ensure the roofing cement bonds effectively and eliminates potential trapped moisture.
Do I need to put tar paper under rolled roofing?
Yes, installing a base layer of roofing felt (tar paper) is a mandatory step for a durable installation. This underlayment acts as a secondary barrier against moisture and protects the roofing material from resin in the wood sheathing. You should staple this felt layer down smoothly before applying the actual rolled roofing sheets.
How long does rolled roofing last on a shed or garage?
Most mineral-surfaced rolled roofing systems have a lifespan of 5 to 10 years, depending on the climate and amount of direct sunlight. While it is cost-effective, Core Commercial Roofing & Coatings notes that it has a shorter service life compared to commercial membranes like EPDM, so regular inspections are necessary to get the maximum longevity out of the material.
What type of nails should I use for rolled roofing?
You must use galvanized roofing nails with a large head, typically 11 or 12 gauge, to hold the material securely without tearing through the asphalt. The nails should be long enough to penetrate through the roofing and the wood sheathing underneath. Always space them 6 to 12 inches apart along the edges and cover the heads with cement to prevent leaks.
How do I seal the edges of a rolled roof?
To waterproof the perimeter, you need to install metal drip edging along the eaves and rakes and seal it with roofing cement. You must apply cement over any exposed nail heads and under the edges where the roofing meets the metal. Core Commercial Roofing & Coatings advises that paying extra attention to these perimeter details is crucial to prevent wind uplift and water from curling back under the deck.
Why is my new rolled roofing rippling or bubbling?
Ripples and bubbles usually occur because the material was not allowed to warm up and relax in the sun before installation, or because moisture was trapped underneath. If the deck was damp when you applied the roofing, the water vapor will expand in the heat and push the roofing up. Always ensure the wood deck is perfectly dry and the material is flat before nailing.
Is rolled roofing cheaper than asphalt shingles?
Yes, rolled roofing is significantly cheaper per square foot than standard asphalt shingles and much faster to install. It is the most budget-friendly option for non-living structures like sheds, workshops, and carports. However, it is strictly designed for low-slope roofs and does not offer the same aesthetic appeal or long-term durability as architectural shingles.
How do I maintain a rolled roof to make it last?
Routine maintenance involves clearing debris like wet leaves that trap moisture and ensuring your gutters are flowing freely to prevent standing water. You should also check for blisters or open seams annually. According to Core Commercial Roofing & Coatings, catching small seam separations early and resealing them with fresh plastic cement is the most effective way to prevent major water damage.
