Special guest post from Duane Craig of Construction Informer, thanks Duane!
[ed. ] If you’d like to write a guest post on Green Roof Plan, please get in touch here.
Building a green roof as a do-it-yourself project is not for those who have an aversion to demanding physical labor or who have little interest in building things. Reinforcing an existing roof requires attention to details, and feeling confident that you’ve just installed the waterproofing barrier correctly requires confidence in your ability to understand instructions that may use terms unfamiliar to you. For many people who want a green roof the best way to get it is to hire someone to install it.
Finding a company near you that specializes specifically in green roofs may not be possible. If you do find one, it may be the only one, so you will be limited in your ability to compare the quoted price with that of another contractor. Still, when this is an option it offers you the advantage of having the entire installation handled by one firm. That way, if there are ever problems, you know for sure who owns them.
The different steps in green roof installations require general contractor work, roofing work and landscaping work. Ideally, you will be able to find a general contractor who will then hire the other specialized trades so you only have to deal with the one contractor. Or, you may find a landscaping contractor who has contacts in the other trades who will subcontract their portions of the work. Another scenario is hiring a general contractor to do the roof reinforcement, a roofing company to handle the waterproofing and a landscaping company to install the other green roof components.
Regardless of which way you go there are some basic guidelines you should use in working with the contractors.
Once you’ve found a contractor to work with, you should have at least three candidates to qualify. Ask each for references and followup by contacting the references. Find out how happy the references were with the speed, efficiency, attention to detail, completed work and price. Then check to be sure each candidate is licensed to do business in your community.
When soliciting the bids know what you want the contractor to do and be specific. Think about any elements of the work that might pose surprises like unseen plumbing or electrical in walls or ceilings that will interfere, and ask each bidder to comment on their expectations and how they will handle surprises. Evaluate the bids looking at the scope of work, timing, references, warranties and price. Get a detailed contract from the winning bidder. This should specify the work to be done, how it will be done, what materials will be used, a start and anticipated end date, a warranty, total price including taxes, permits and fees, change order process, review and acceptance process and cleanup. Also ask for proof of insurance at the time of contract signing and request the contractor deliver waivers of liens from all suppliers at the end of the project.
Carefully observe the work in progress every day. Look at the materials and processes in use and confirm they match what is called for in the contract. Find out why substitutions are made and ask for their specifications for your files. Have all change orders in writing and make sure they include the specifics about the change, the materials and processes being used and the cost.
Pay only for work-in-place. Paying in increments is fine as long as the work is substantially completed to your satisfaction and the contractor is not getting paid for work that is substantially unfinished or not even started.