Just want to say that I think you are doing the right thing by getting SALT referral. They take ages to come through (4 months in my case) & if you don't need it as the appointment draws near, you can cancel. Have you also asked to be referred for a hearing test, to rule that out?
My DS2 is nearly 28 months & has his SALT assessment today (I am so nervous!). He has about 10 words & quite a few animal/vehicle/general sounds. He had his hearing tested & fluid was found leading to some hearing impairment, they believe, but he has to be tested again. I am glad that I have taken action early, I asked for both of these referrals at his 24 month check, because even though he may well progress on his own, if he doesn't I am giving him all the help I can. I liken it to a broken leg - you wouldn't leave that, so why leave a speech delay?
We also found that going to nursery 2 mornings per week has helped with DS2's language development greatly - not talking as such, but he now understands a lot more, does actions to songs more, points more - all of which, I believe, will help with talking eventually.
In the meantime, see if you can borrow 'It takes two to talk' by Hanen from your local library, it is very helpful.
Also, I have been given a few strategies from group speech therapy which are quite useful. Firstly, encourage any communication. If he points at a dog & says 'uh' say 'Yes, dog. Big dog. Do you see the dog' etc. Encourage him to make choices - eg hold up milk & water together & make him choose what he wants - this can be through pointing or touching his choice, the important thing is that he's communicating. Set up phrases for him to complete - eg with DS, when we're playing ball, before I throw the ball I'll say 'ready, steady' & won't throw till he attempts to say 'go'. Finally, singing really helps, maybe see if you have a singing group near you (most libraries run them in term times).
I know how worrying this is & I am right there, too, but I really believe we have to do everything we can to help our DC, plus it makes me feel more positive to think that I am doing something. Good luck!