What is the central boss of a conservatory?

If you have a shaped conservatory then you almost certainly have a central boss (sometimes referred to as a crown moulding). It is the “capping” that covers the point where all the shaped rafters meet in the roof.

It is called a boss because that’s the term used for the central cover of a wheel hub (if you look at the plan of a shaped conservatory roof it often looks like the spokes of a wheel radiating out from a central point).

Find Out More

Roof blinds neatly fitted around the central boss moulding of a conservatory

This part of a conservatory is very important when considering blinds because it can often be the cause of ugly gaps, if not done correctly. Things to consider are:

How narrow can shaped blinds be made at the very top?

The top of a shaped blind cannot be made to a point, so it all depends on how narrow (or wide) the apex width at the top of the blind would be.

Our pure Pleated Blinds can be made much narrower than any other shaped roof blind (with an apex width of just 59mm) so this tends to overcome any issues and makes them the roof blinds of choice. Most other roof blinds require a 100mm shaped top, so they tend to leave large gaps.

Is your boss the same shape as the eaves of your roof?

A lot of conservatories have a different shaped boss from the actual roof. As the top of a shaped blind is flat and must be parallel to the base of the blind then, if the boss has a different shape, then there will be unavoidable gaps.

Having said that, these gaps are normally tiny and almost invisible, and even if they aren’t then they can be filled with UPVC, but this cannot be guaranteed to last.

Does the boss intrude over adjacent glazing?

If the boss is very big it may overlap well past the junction of the shaped rafters and start to cover the adjacent glazing. If this happens, then the adjacent blind cannot be cut around this, leaving just two options:

  • Replace the boss – not many people are willing to do this but it is by far the best option
  • Create an infill blind – this is the most common option and can be extremely neat

Search our conservatory blinds image gallery to see just how neatly our blinds fit compared to all others.

Related Questions


Can't find the answer to your question?

Click here to Ask an Expert

Contact Us

Free Quotation Free Brochure Ask an Expert


What areas do we cover?

What areas do we cover?

EXTRA savings, up to

50% off items

Free brochure

Request a free brochure

Free quotation

Arrange a free quotation
Ask an Expert close

To arrange a free quotation please complete the form below.

Have any questions?

Real conservatory blinds experts are happy to answer your detailed questions. We cannot always offer an immediate reply but we will get back to you as soon as possible