can you seal a roof from the inside

Can You Seal a Roof Leak From the Inside?

Fixing leaks from within is not intended as a long-term solution, and should only serve as an interim measure until you can afford professional roofing repairs.

Locate and follow up on any leaky spots on your roof by tracing back their source. This may prove tricky as water often flows along your rafters or decking, making its way toward its source.

Go outside using a pair of binoculars to check for evidence of leaks such as curled or cracked shingles, weakened flashing and caulking, or end caps that are tent-shaped and can be penetrated by rainwater. These are the most common sources of roof leaks, but you can also see them on curved roof edges and in any areas where shingles butt up against other roofing materials.

Plastic Sheeting

If you need to seal an internal roof leak, there are various solutions available; plastic sheeting being one such choice.

Protecting your roof with rain protection can be an excellent way to ensure it stands up against rain and other elements, but choosing the appropriate material is crucial. Thick enough to cover leaky areas while being UV resistant so as to not prematurely degrade.

Polyethylene film used in most plastic sheeting is designed to withstand even the harshest environments and climate conditions, making it suitable for construction and agriculture use. Such polyethylene films are sometimes referred to as C&A Film or construction and agriculture film as they’re commonly utilised by builders and agriculture specialists in protecting lumber, skids of materials, or any other items left outdoors during building processes.

Home stores typically sell 3-6 mil plastic sheeting, while more specialised companies carry thickenings tailored to specific tasks. No matter which option is right for your project, you can find quality plastic sheets at competitive prices to protect your roof against damages and leakages.


Tarps can be an effective means of sealing a roof leak from within. Simply purchase one at your local hardware or home improvement store and use it to cover the area where there is leakage on your roof.

These tarps are constructed with strong materials that resist weather conditions, abrasions and other environmental threats such as mildew. You can treat them against mildew for additional protection against mildew growth.

Retractable roof covers can help protect your home from rain or snow, as well as protect holes or missing shingles from leaks.

To keep the tarp in place, you’ll need to secure it correctly. Heavy concrete blocks or nailing it to the roof ridge may work effectively in this regard.

Check your tarp’s weave count; higher numbers indicate heavier and more resistant fabric that won’t tear as easily. Also ensure that its seams are stitched and heat sealed so water cannot seep through their seams.

Roof Sealant

Homeowners should select a sealant type appropriate to their roof type and material – some include silicone while others might be water-based or thermoplastic.

Sealants can be applied using either a paintbrush or roller, while some come in tubes to be used with caulk guns for more detailed repair work. They can be applied directly onto roofing shingles as well as rubber membranes and metal roofs.

Polyurethane sealant can provide an effective waterproof barrier, stopping moisture from passing behind flashing or through gaps and tears. Unfortunately, polyurethane sealants do not offer much UV ray resistance – thus making them unsuitable for areas exposed to direct sunlight.

Liquid rubber sealant can also be an excellent choice for fixing leaky shingle roofs, and can be applied using paintbrush, sprayer or roller. Plus, there is a variety of colours to choose from!

Adhesive Tape

Adhesive tape is a product made up of a backing material coated with adhesive and used across industries for various applications.

Paper, plastic film, cloth, foam and foil are among the more commonly used backings; each material boasts unique properties to meet specific bonding requirements.

An equally critical consideration is the adhesive itself. Adhesives may be pressure-sensitive or thermally activated; some even need moisture in order to activate.

There are various adhesive types designed to bond to various substrates. Certain formulations of glues have been specifically created to adhere to low surface energy (LSE) or high surface energy (HSE) surfaces.

Tape must possess an adhesive layer thick enough to ensure strong adhesion between materials, which explains why some varieties, such as duct tape, may have thicker adhesive layers than others.

Adhesive is a substance that forms bonds with surfaces through molecular interactions. It uses both adhesion and cohesion, which allows it to stick to its substrate, but also stick to itself as well.

There are four basic mechanisms that enable tape to bond with a substrate surface. These include chemical adhesion, mechanical interlocking adhesion, repulsion, and polarisation.

Read our other article: How to Find and Stop a Leak

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