How to Care for Your Slate Roof (and What Could Happen If You Don’t)

slate roof maintenance new jersey

“Repair or replace” is a perennial question when homeowners start to spot roof damage. Slate lasts a lot longer than many roofing types, but eventually that old question will have to be asked.

Slate has a long history and has been a traditional American favorite, praised for its surprising versatility, elegance and impressive durability. It wasn’t used on European castles for nothing.

Today, slate remains a popular choice with American homeowners who prize practicality and a picturesque finish. It’s tough stuff, but even slate can weaken beneath the elements or at the hands of poor craftsmen. Here are some telltale signs that identify a struggling slate roof and what can be done to maintain its beauty.

The worse for weather

Ultraviolet radiation is always there regardless of cloud cover, draining the color from slate as the years pass. The rays break down the chemical makeup of the slate tiles, drying them out and rendering them far more fragile.

Rain, whether steady or torrential, can crack the then-brittle slate. From there, the steady pounding of rain can work its way through and into a home. 

Strong winds can also crack, loosen or lift slates off completely and expose/erode sections of your home. With slate being a heavy type of roofing, any weakening of structural integrity could spell an eventual collapse. Wind also carries debris, which can lodge beneath tiles over time and cause further wear and tear.

Loose tiles are often easy to spot from ground level, but catching the first appearance of a crack may take a long time. The process greatly speeds up once it begins. Cracks allow moisture through, which ruins individual tiles and causes bigger problems.

If you see even a single crack, some minor repairs are in order before it becomes a wider problem. Since your roof is “way up there” you may not spot cracking without climbing a ladder, but you can certainly see signs of a weakening roof from indoors.

Moisture, mold and leaks

Cracked tiles should be thought of as breeding grounds for mold. You may have seen slate roofs with a green tinge to them; that’s where mold has taken root in the water-retaining tiles. It doesn’t take long for that problem to creep indoors, where it will compromise the health and well-being of the occupants.

If you see any external greening or internal leaks or damp spots, we recommend hiring a professional to clean the slates – it can be a messy and hazardous job working at height with a slick surface. You may also notice some powdering on the underside of the slates from indoors.

A resonance test can indicate how strong the slates are. Gentle but firm tapping on each tile should produce a crisp, sharp sound. Anything duller than that indicates a deterioration in their quality. 

Homeowners may find that the mold problem has too much of a grip, and that’s when replacement roofing would be the safest choice.

Weakened flashings and fasteners

Roof flashing comes in many forms (you can learn more about it here), but its purpose is always to provide a layer of sealant between the outside world and your home. Flashing protects the roof surface and vulnerable spots of the structure such as roof valleys, chimneys or skylights. Weakened flashing is a sure way for slate to suffer.

Fasteners are the nails that hold slate tiles in place. Solid workmanship and maintenance can allow nails to last a very long time. The absence of both of those means fasteners are just as vulnerable to the weather as tiles are, becoming rusty and weak. Any evidence of weakening nails is a bad sign for a slate roof.

Minor maintenance here and there is relatively inexpensive. It can become financially impractical if it happens too often or if a large percentage of the roof has been compromised. What can be done if repair or replacement is necessary?

Blue Nail Roofing can provide a historical appearance with evolved materials

Today’s homeowners have the perfect solution to the “repair or replace” question. Modern production makes it possible to have all the prestige of a repaired or replaced slate roof with none of the traditional trouble.

At Blue Nail, we install DaVinci Roofscape, a composite slate-and-cedar product that perfectly captures the appearance of natural slate. It comes in multiple widths and colors and surpasses the resilience of natural materials: It scores a Class A fire rating and a Class 4 impact rating, and it can handle hurricane-level winds of 110 mph.

It’s guaranteed for life without yearly maintenance, showing little to no fading and no cracking or flaking (also known as delaminating). The result is so effective that historical structures are choosing DaVinci Roofscape to replace their compromised original slate. They know the structural and cultural integrity of the building will be maintained.

Even medical facilities trust this modern option because without cracks, the patients under that roof won’t have to worry about mold. That’s a strong stamp of approval for homeowners in the Morris County area looking to add some long-term class and comfort to their home. 

Whatever your roofing questions may be, Blue Nail would be happy to share our insight with you. Get in touch at the details below for some friendly advice.
Working with Blue Nail Roofing means coming home to craftsmanship. From first call to final inspection, we’re with you every step of the way to ensure you benefit from our experience and background in old school slate construction and many other services. For more information or a free consultation, drop by our contact page.