Free quote
Australia Wide Delivery - 100% Australian Owned

How to install a window sill with scotia

Everything you need to know in easy-to-follow steps and video guides.

How to install a window sill with scotia

Planning & preparation

Ensure you have the required tools and equipment to complete the job.

Tools & Equipment

  • Caulking Gun
  • Hammer
  • Carpenters Pencil
  • Nail Gun
  • Intrim Intense Glue
  • Tape Measure
  • Selleys Aquadhere PVA Wood Glue
  • Combination Square
  • Cordless Drill

Step-by-step visual guide for installing a window sill

1 Mark quirks on window frame reveal

To determine distant sill sits below the window reveal.

2 Measure length of sill and scotia overall

Measure to the outside of architraves plus allowance for sill overhang past the architraves plus wastage.

3 Cut sill and scotia to approx. length

Cut mitre to one end of sill and square cut on the other end to the length determined in step 2.

4 Determine overall length of sill

Fix resting blocks on wall to rest the sill on while marking the corner point on sill to cut the mitre on.

5 Cut sill to exact length

Cut mitre on the other end of the sill. Mitre cuts should be on both ends of the sill ready to install.

6 Install sill

Predrill both ends of the sill to be used for fixing with nails or screws. Apply glue to the back face of the sill and fix it into place, ensuring it is aligned with architraves at each end. Predrill the remaining sill and fix and punch nails or countersink screws.

7 Mitre cut sill returns

Check for a neat fit.

8 Install sill returns

Apply glue and position ends in place. Fix join with fine finishing nail and wipe away excess glue.

9 Lightly sand mitre joins on both ends of sill

Remove resting blocks from underside of sill.

10 Determine length of scotia

Align scotia to mitre cut on the underside of the sill. Determine the length of the scotia and mark the cut at the mitre join on the opposite end of the scotia.

11 Cut scotia to length

Cut mitre on the other end of the scotia to the exact length determined in step 10.

12 Mitre cut scotia end returns and install

Check ends for a neat fit. Then apply adhesive to the back faces of the scotia and fix it in place with nails. Apply glue to ends and push in place and wipe away excess glue.

Frequently Asked Questions

What is a Scotia?

Scotia is a decorative moulding used to cover the gap of an internal corner between two materials. Examples include between the timber flooring and a skirting board, as well as between the underside of a sill nosing and wall.

What is the moulding that fixes under the Sil Nosing?

You can fix any decorative bead. A popular moulding is the Scotia. SN23 is a detailed Sil Nosing option.

How far should my Sil Nosing stick out from the wall?

There is no hard and fast rule about this. If you are wanting to fix a scotia or decorative moulding underneath it should project enough to allow for the selected moulding to fit. Generally the max is 66mm.

Get a free quote today

We aim to turn around quotes within 1 business day!


    This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

    Download PDF brochure

    Get a free quote today

    Fill in the form below to receive your free quote

    How can we help?

    Enter your details below to let us know how we can help with your enquiry

    Free design consultation

    Enter your details below to let us know how we can help with your enquiry


    Shopping basket


    1 of 4


    2 of 4


    3 of 4


    4 of 4

    Product basket

    Need technical drawings?
    Tick here if you require technical drawings of your selected profiles.

    Specification Sheet
    Store all your favourite profiles here.

    Specification Sheet

    Quote Request
    Store all your favourite profiles here.

    Quote Request