Estimating green roof installation cost


How much does it cost to install a green roof?

Cost of green roof installation will depend on a number of factors and total expenses primary determined by materials prices per square to build a live roof and labor cost to complete the work. While calculating gross expenditures for installing the green roof a number of additional factors should be taken into account. Contractor who specializes in green roofing systems installation will calculate the cost after the roof inspection, getting detailed measurements and analyzing work complexity. Itemized estimate will reflect all charges and fees associated with the installation. Materials cost will be calculated separately and added as a separate expense.

Calculating green roof installation cost

Materials prices materials-prices

There are different green roofing systems available on the market for flat or sloped roof. Prices will be defined by the cost of materials for waterproof layer, drainage system and actual soil or grows substrate layer for planting green plants.

Determining labor cost for green roof installation labor-cost

Cost of man power will depend on a roof size, design and overall work complexity. Installation of green roof is complex a few steps process. Many roofing contractors are able to install standard waterproofing roofing materials to protect house structure and the work will be estimated at the same charge per square as a regular roof. While installing a live roof additional steps should be taken and all extra work will be quoted as separate fees.

If the house structure was designed for lightweight flat roofing materials such as EPDM, TPO or modified bitumen membranes roof joists, rafters, trusses, or the whole roof structure have to be reinforced to support heavy load of green roof. On older houses preparation work is nearly unavoidable and will be calculated as extra charges.

Installation of green roof on a slope, especially if the roof pitch greater than 8/12, will be estimated at higher rates comparing to completing same size project on a flat roof.

Shopping for a new green roof shopping

The overall expenses to purchase and install a new green roof will greatly depend on the condition and suitability of an existing roof to accommodate live plants. If the roof covering materials do not have to be replaced and a 4” – 12”+ in depth growing medium layer including the drainage system can be placed directly on its surface you do not have to buy and install actual waterproofing layer. Otherwise proper roofing materials have to be purchased and install prior to putting soil and plants on the roof. Before making a final decision it is always better to consult with a local roofing company which can inspect the roof and recommend which products to choose based on a roof resign, climate zone and building codes.

Estimating installation time estimating-time

Difficulty of work, labor availability and project size will define the time required to complete the work. Normally installation of 3,000 square feet of a green roof on a 40 squares flat roof of a 2 story house is one day project for an experienced crew. Installation of 60 mil EPDM membrane and flashing work can be completed in 8 – 9 hours by a roofing company. Accurate number of man-hours will be estimated after analyzing all the details.

Work complexity work-complexity

Technically installation of a live roof excluding waterproofing the roof with rubber, PVC, or other membranes as well as if no roofing materials have to be replaced is a simple project. Some handy homeowners are able to manage proper installation of a drainage layer on the flat roof, putting soil media and plant green plants unless mowing thousands pounds of soil on the roof will be out of any considerations. But proper installation of roofing materials is much more complex task and it is always better to hire professional roofers who will ensure adequate roof performance to complete such work.