Gillies & Mackay Shed Conditional Guarantee

Your Gillies & Mackay Shed is guaranteed for 30 years. 

Of course, we didn’t just pluck this number from the air. We can offer you this guarantee with complete confidence because we’ve seen firsthand how our buildings perform. We’ve been building Garden Rooms, Garages and Sheds since 1989, and with the right care, those early buildings are still standing firm all these years on. 

Every decision we make contributes to the durability of our buildings and the quality of our workmanship. We choose the best materials for the job, selecting the best-quality timber for our cladding and framing. Where appropriate we use pressure-treated and thermally-treated wood that is incredibly resistant to water, rot and insects. 

We put all our experience, knowledge and expertise into producing 30-year buildings, and then it’s over to you. We promise to uphold the terms of the Guarantee, and you promise to care for your building. But don’t worry – you’re not on your own! Our Aftercare Guide has all the information you need to ensure that your building endures and surpasses the guarantee period. The combination of our craftsmanship and your care is what makes a Gillies & Mackay building last a lifetime. 

Here’s everything you need to know:


This Guarantee is valid for 30 years from your delivery date, subject to the conditions outlined below. It applies to your Shed and covers defects in materials and workmanship. 

During the 3-month settling-in period remedial adjustments may be required, typically doors/windows or defects unidentified in our quality control processes.

Under the terms of this Guarantee, any defects relating to workmanship will be remediated and any failed components replaced.

You may return your building within 14 days of delivery, after which you will be refunded the cost of your building minus the deposit. Gillies & Mackay are not liable for any costs relating to groundwork or electrics for a returned building. 

In the event of any unresolvable ongoing recorded dissatisfaction, the returns period is extended to 6 months, after which a refund minus the deposit will be issued. 

Outwith these 6 months, a compensation refund will be issued at a discretionary amount calculated on usage and the age of the building upon return.


General Maintenance

The Shed’s structural integrity and resistance to moisture and rot are dependent on your maintenance of the building. 


Your Shed comes with a base coat of Sadolin paint. A further coat of Sadolin should be applied within 3 weeks of delivery. A full recoat of Sadolin should be applied every 3-5 years depending on environmental exposure.  Only Sadolin Quick Dry or Sadolin Superdec should be used. Your paint colour can be found on your order form.

Incorrect application or use of non-recommended products will void this guarantee.


Your Shed has Steel box profile roofing which is guaranteed by the manufacturers for 20 years. This does not cover damage due to external forces or improper gutter maintenance. This guarantee covers the integrity of installation but does not supersede the manufacturer’s guarantees, the terms of which must be adhered to.


If installed, guttering should be checked and cleaned at least twice a year, and more frequently if trees overhang your building. Failure to maintain the guttering can lead to water damage, which is not covered under this guarantee.


Your Shed comes with a timber floor, which can be left uncovered or protected with a flooring material. Glueing or sealing flooring materials can cause damage to the timber floor. Any such damage is not covered by this guarantee.  To clean your shed floor, avoid using wet mops and opt for disposable floor wipes to prevent moisture buildup. Excess moisture damage to flooring due to improper care is not covered by this guarantee.


Your Shed should be ventilated regularly to prevent moisture buildup which could lead to condensation and mould. Sheds must be ventilated fortnightly and more frequently during prolonged wet weather, as described in the Aftercare Guide. Any excess moisture from wet items or liquid spills should be dried off immediately. This guarantee does not cover any damage due to moisture accumulation inside the Shed caused by inadequate ventilation.

Moisture Management

Any signs of moisture ingress should be addressed immediately by increasing ventilation and possibly using moisture traps or a powered dehumidifier if the Shed is equipped with electricity.


The entire door, including front, back, and edges, must be thoroughly coated with paint to prevent sticking or shifting. Natural timber frame movement over time is normal and is not considered a defect. If door adjustments are necessary due to excessive movement, this must be done by a qualified carpenter at the owner’s expense.


As well as the exclusions noted above, this guarantee does not cover damage due to improper use, unauthorised alterations, natural disasters, normal wear and tear, natural fading of materials, or superficial damage.

This guarantee does not cover issues arising from non-compliance with the aftercare instructions provided in the Gillies & Mackay Shed Aftercare Guide.


All claims under this guarantee must be made with proof of maintenance compliance, including receipts for materials used and records of maintenance activities.

This guarantee ensures that the product is maintained as intended, protecting the integrity and longevity of your Shed while clarifying the responsibilities and expectations for care. If you need additional details or modifications to this draft, please let us know by emailing