Everyone hates additional costs wherever they go, and especially on big ticket items like a new roof for a house. Unfortunately, the nature of roofing projects means that sometimes there will be unforeseen additional costs that can come up during the installation. While a homeowner might request to change any number of aspects about their project, there are somethings that are unavoidable once they are discovered. Here is a few common roofing change orders to look out for and prepare yourself in case they come up on your roofing project.

  1. Dry Rot/Fungus DamageDry rot is a type of wood decay caused by certain species of fungi that digest parts of the wood which give the wood strength and stiffness. It’s called ‘dry rot’ because the wood often appears to be dry and crumbly. However, the fungus responsible for dry rot typically requires some moisture to begin its growth, so the term can be a bit misleading. Dry rot typically occurs when there is a leak in the roof and water is saturating the wooden structure beneath the roof material. The damage compromises the structural integrity of the roof, and must be replaced. However, the damage is often not visible until only after the old roof is completely removed and therefore it is almost impossible to tell how much wood will be replaced before the existing roof is removed.

    Fungus can cause serious damage the roof structure

    Dry rot is also found in situations where a roof has poor ventilation, and sections of the attic are holding humid air. This is part of the reason why proper attic ventilation is extremely important for the lifespan of a roof. It is also commonly found on the edges of the roof structure on what are called the fascia boards. These pieces of wood hang under the edges of the roof and are the most exposed to the elements, so they are often in need of replacement at the end of a roofs lifespan.

    What can you do?

    There are a few preventative measures that can be taken to reduce the risk of dry rot occurring on a roof. The most effective measures would be to make sure the roof is not leaking, making sure the roof is properly ventilated, and using proper roofing components such as drip-edge, starter strips, proper metal flashings, and ice-and-water barrier in the valleys of the roof. These components will not guarantee that dry rot does not occur, but they will definitely increase the performance and lifespan of the roof.

    The cost to repair dry rot damages on a roof is extremely variable, with many projects needed no repairs at all, and others costing over $4,000. We see about an average of cost of around $1,400 on our projects that need dry rot repairs.

  2. Additional layers of roofing materialAnother common roofing change order is for the removal of additional layers of roofing material that were not removed during previous roofing installations. Although most roofing contractors nowadays will recommend removing all existing roof material before installing a new roof, it is still common for older buildings to have 2, 3 or even more layers of old shingles, wood shakes, or modified bitumen systems existing underneath the current roof. Property owners sometimes did this in a short-sighted attempt to save money by not having to pay for the removal of the old roof when it is being replaced, but this leads to additional cost because of the extra labor costs and dump fees associated with removal and disposal of this extra material.

    Some roofs have multiple layers of material

    With asphalt shingle roofs, these additional layers can usually be spotted from the edge of the roof by lifting the shingles up and inspecting to see if there are old shingles below. However, this is not always possible, as sometimes the shingles won’t be visible from the edge, and other roof types such as flat roof systems are not able to lifted up for inspection.

    There are other, more destructive methods to determine exactly how many layers of material are on every section of the building, but sometimes despite all efforts it is only discovered during the demolition of the old roof. In this case, a change order will be necessary to cover the cost of dealing with the additional material. So if you know how many layers of material are on the roof, tell your contractor!

    The cost to remove one additional layer of asphalt shingles on a 2,000 sq ft house is anywhere from about $800 to $2,500.

    Watch this short video to learn more about additional layers and how to see them.

  3. Plywood sheathingPlywood sheathing, also called sheeting or decking, is the wooded substrate that supports the roofing material. On some older buildings, the sheathing is made of wooden boards with large gaps in between them, which will need to be covered with plywood sheets in order to install a new roof. The installation of plywood sheathing can be quite a significant change order for those that are not expecting it. Unfortunately it usually comes with an additional layer change order as well, as the likely scenario for needing new plywood sheathing is when the building has a layer of old wooden shake roof material. Wooden shakes are often hidden underneath some other form of roof material, usually asphalt shingles or stone-coated metal, so definitely take a look in the attic to see if you can see any wood shakes through the rafters.

    Plywood needs to be installed over skip-sheathing

    If the roof needs plywood sheathing, it can add quite a bit of additional cost due to the price of plywood. Fortunately, this is something that can almost always be discovered before any work begins on the project, so any additional costs required can be factored in before the work begins.

    The installation of new 1/2” OSB plywood sheathing on a 2,000 sq ft house is anywhere from $5,000 to $8,000 or more depending on the price of plywood.

    Watch this short video to learn more about plywood sheathing and how to determine if it is needed.

  4. Gutter ReplacementsReplacing gutters is sometimes needed if they are damaged or not working properly. This change order is less important than the other three, and some jurisdictions care more about the condition of the gutters than others. It is definitely worth getting the gutters replaced if they are damaged or are not functioning properly, but if it brings a project over budget it might be something that can wait. However, some building departments will require gutters to be installed on a house, and if they are already installed they might require that gutter screens/ gutter guards be installed as well. Please check with the requirements of your local building department to see what the regulations on gutters are.The typical cost to replace gutters on a 2,000 sq ft house are anywhere from $1,500 to $4,000.

Gutter replacements are sometimes needed

These are some of the more common change orders that occur on reroofing projects, but by no means is this an exhaustive list. If you have an upcoming roofing project an are worried about potential change orders, feel free to reach out to the team at BidList and we would be more than happy to share out expertise with you.