Disabled Checked checkbox shows as unchecked - ASP.NET

I have a input checkbox that is checked and disabled when some JS runs on page load.

<input name="selectUnionDues" id="selectUnionDues"  type="checkbox" checked="checked" runat="server" />

When I get the value of the checkbox by using (on the server side)

this.selectUnionDues.checked //returns false

I always get a false

EDIT: I am concerned about using heavy asp.net controls since the page size in this application needs to be low. Is there a way out using HTMl controls?