How Do You Repair an Old Slate Roof?

A Slate Roof

There are many different sizes, styles, and ages of homes in the Dallas, Texas area.  Some of the older parts of the city were built to last, including having a slate roof. Repairs are necessary on the structures, however, including the roofing. However, slate roof repairs require an experienced contractor who has worked with slate roofing material.   

When a slate roof is damaged, replacing it can be costly, depending on the size of the home. The cost can start around $10,000 and go upward of $50,000 or more. Is it worth repairing a slate roof? Absolutely, after you get price quotes to replace the slate with slate, the possibility of having professional slate roof repairs is the more cost-effective option. 

However, the age of the roof and the extent of the damage can have an impact on slate roof repairs.  If the roof has reached its prime of 100 years or older, has extensive damage, and depending on the method used to complete the repairs, it could make the cost inconceivable. 

What are the methods of slate roof repairs? 

Two acceptable methods for slate roof repairs that require the slate tiles to be replaced. Those two methods are:

  • Nail and Bib: This is the most used slate tile repair/replacement method. The contractor will remove the broken slate tile with a slate ripper.  The replacement slate tile is then anchored to the roof using a nail that is inserted between two slate tiles. Then the row above is returned, overlying the new slate tiles. 

A small square of flashing made of aluminum, copper, or other corrosive-resistant metal is slid under the two slates and overlying the next course above the new slate tile and over the nail head. 

  • Slate Hook: This method is done by using a 3” long hard wire hook made of copper, galvanized steel, or stainless steel. A small, exposed loop hooks to the replacement slate, pulling it into place. The hook is left, which is why they are typically a color that blends with the slate. 

Can cracked slate roof tiles be repaired instead of replaced? 

If the cracks are minor, then yes, a waterproof sealant can be used to repair the crack. However, it is recommended to have the entire roof inspected, especially around the cracked slate tile. Depending on the extent of the damage and if there are any issues like structural or wood rot issues, a slate tile roof replacement may be the better option. 

What are the downsides of a slate roof?

Slate roofing was commonplace in the early settlement years of Dallas, and for a variety of reasons, it has become a popular choice. Those reasons include the aesthetic, and unique beauty it gives a home. You can get a distinct look with wide choices in colors, sizes, and thickness. The long, long lifespan, environmental friendliness, weather resistance, and everlasting durability are key reasons people are choosing a slate roof. Repairs are the biggest downside to this roofing material, but there are other downsides too, including: 

1. The Weight

A significant issue with having a slate tile roof is the weight. Because of the significant extra weight of these tiles, up to 800 pounds per SF, the structure should have an engineering inspection before installing the slate tile. A house that isn’t approved by engineering can end up collapsing under the weight. 

2. The Installation 

The installation of slate roofing is challenging and time-consuming. Depending on the size of the home and where the slate tiles are coming from, the installation can take up to 3 or 4 months. 

3. The Repairs

Not only is the installation difficult for a slate roof, repairing it can also be just as difficult. The first challenge in the repair process is finding new slate tiles that match the existing tiles. Slate is a natural material that is found in a variety of colors, shapes, sizes, and thicknesses. If a slate roof repair requires replacing any of the tiles, they most likely are not going to 100% match, which can affect the overall aesthetics.

4. The Fragileness

A slate roof can be confusing. On the one hand, we’re told they are durable. They can withstand the weather, fire, and more. Yet, it is also a fragile material. Foot traffic is discouraged because stepping on the tiles in the wrong manner can break the tiles. This is why slate roof repairs should only be done by an experienced contractor who has the knowledge and proper equipment to complete the job without causing more damage. 

5. The Installers

Just as with slate roof repairs, the installation should be done only by an experienced contractor. Because the installation process itself is challenging, and the tiles can be easily damaged if mishandled or installed wrong, it can be hard to find a local roofing contractor with slate tile experience. 

6. The Cost

This may be the number one reason why more homeowners do not choose slate roofing. The upfront cost is as much as 5x more than asphalt shingled roofing. 

In  Conclusion

So, with all of this information, you have to wonder if a slate roof is worthwhile. From the homeowner aspect, if you’re going to stay in your home for the unforeseen future, yes, a slate tile roof is worthwhile. But if flipping it may be on the nearby horizon, it can raise the value of your home, but may not be enough to recoup the cost.