I want to remove a section of one ceiling joist to gain bett...

[KFill]

I want to remove a section of one ceiling joist to gain better access to the attic which will be used for storage. Will I compromise the strength of the ceiling / roof too much?

[concord carpenter]

Yes. You can still do this as long [as the framing are not truses] but you need to frame the opening properly.

A common ceiling joist can be cut back or away as long as your reimforce the two joists on either side of it. Many people do this in order to accomodate an attic pull down ladder.

Frame the opening using the same size floor joists or larger as are currently present in the attic. Attach additional joists to the existing ones on either side of the opening. run them full length making sure they are properly supported. this is called "sistering."

Use joist hangers to attach two joists at a 90degree angle between the sistered joists at your opening. Use structural joist hanger nails.