FAQ
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Principles
How does capillary action affect slate aging?
What are the specific processes that age roofing slate?
Why do certain types of roofing slates show different aging patterns?
Scope of use
Can I use SlateSpacer™
• with Scottish-style head-nailed slates?
• with single lap, interlocking roof slates?
• with roofing slate hooks?
• on a slate roof with a closed (board or plywood) deck?
• with any roof slate thickness?
• with random-width roof slates?
• with any slate head lap?
Performance
How long does a slate roof that uses SlateSpacer™ last?
Does spacing roof slates with SlateSpacer™ introduce a weather-entry problem?
Does spacing roofing slates with SlateSpacer™ introduce a breakage problem?
Purchase
Other
Are there other spacer systems for slate roofs?
Do the various single-lap roof slate systems, that use non-slate materials beneath roofing slates to achieve a water-tight roof, provide a similar benefit to SlateSpacer™?
Principles
Q: How does capillary action affect slate aging?
Q: What are the specific processes that age roofing slate?
Q: Why do certain types of roofing slates show different aging patterns?
Scope of use
Q: Can I use SlateSpacer™ with Scottish-style head-nailed slates?
A: Yes, there is no difference between head-nailed and edge-nailed installations of spacers.
Q: Can I use SlateSpacer™ with single lap, interlocking roof slates?
A: No. SlateSpacer™ is for use with double lap, non-interlocking slates.
Q: Can I use SlateSpacer™ with roofing slate hooks?
A: Yes. SlateSpacer™ can be used with nailed or hooked slates.
Q: Can I use SlateSpacer™ on a slate roof with a closed (board or plywood) deck?
A: Yes. SlateSpacer™ can be used on open or closed roof decks.
Q: Can I use SlateSpacer™ with any roof slate thickness?
A: Current models of SlateSpacer™ are sized for the most common slate thicknesses, namely, from 4 mm to 10 mm (~5/32" to ~3/8"). Please contact us if your slate is another thickness.
Q: Can I use SlateSpacer™ with random-width roof slates (varying widths next to each other)?
A: Yes. A minimum side lap of 75 mm (3") should be preserved. Please contact us if you wish to use a smaller side lap.
Q: Can I use SlateSpacer™ with any slate head lap?
A: Current models of SlateSpacer™ are sized for the most common head laps, namely, from 75 mm to 125 mm (3" to 5"). Please contact us if you wish to use another head lap.
Performance
Q: How long does a slate roof that uses SlateSpacer™ last?
A: The evidence predicts that SlateSpacer™ will extend roofing slate life by many decades, in the case of high quality slate, and by many years, in the case of low quality slate. This is because SlateSpacer™ lets slates dry 8X faster, resulting in a dramatic reduction in the time during which aging processes can occur. In the simplest terms: The processes that age slate require water; slate traps water (as do other overlapped roofs), and SlateSpacer™ frees trapped water.*
* Drying tests, the archeological record, examination of old slates and a modern understanding of the processes that age stone — all predict substantial lengthening of slate life. Learn more about how water ages stone, how roofing slates trap water and how SlateSpacer™ frees trapped water.
Q: Does spacing roof slates introduce a weather-entry problem?
A: No. The 1.2 mm (< 1/16") gap that SlateSpacer™ introduces is smaller than other gaps that already commonly exist in slate roofs. Joint spaces (the channels between slates) are often up to 4 mm (~3/16") tall and wide, or more, and thickness variances of adjacent slates are commonly 2 mm (~3/32"). Over the centuries, standard overlaps have been well worked out to accommodate these openings. Because it reduces capillary action, SlateSpacer™ actually reduces the most persistent form of water penetration.
Q: Does spacing roofing slates with SlateSpacer™ introduce a breakage problem?
A: No. And, with respect to damage caused by improper nailing, it helps. Learn about walk testing and how SlateSpacer™ reduces breakage.
Purchase
Q: Where can I buy SlateSpacer™?
A: You can purchase SlateSpacer™ on this site using your credit card or PayPal account. If you prefer to buy through a distributor, please contact us.
Other
Q: Are there other spacer systems for slate roofs?
A: No. We are the inventors and developers of the slate spacer concept. SlateSpacer™ resulted from a two year research effort to develop the most effective possible spacer for roofing slates. The effort involved hundreds of designs, scores of prototypes and several patent filings in several countries.
Q: Do the various single-lap roof slate systems, that use non-slate materials beneath roofing slates to achieve a water-tight roof, provide a similar benefit to SlateSpacer™?
A: No — apples and oranges. SlateSpacer™ increases roof and slate life — single-lap slate systems reduce weight.
A roof is only as long-lived as its shortest-lived element. SlateSpacer™ is made of stainless steel, which matches slate life. The water-shedding components of single-lap slate systems are made of fabric, plastic, or galvanized steel, which do not last as long as high-grade slate and cannot extend roof life (but they are well-suited to the aim of weight reduction).
Another distinction between the systems is that SlateSpacer™ is designed to minimize capillary action around the part itself. The elements of single-lap systems are not: like slates, they provide a lengthy capillary path. Because of how the elements are situated, capillary action can extend nearly the full length of the slate. (It should be understood that while single-lap systems do not minimize capillary ascent, the overlaps used by the better systems do prevent water from entering the building they cover, just as properly installed un-spaced slates do).
The two systems are simply designed to address different requirements.