diff --git a/package.json b/package.json
index c5db1ea..a1f07e0 100644
--- a/package.json
+++ b/package.json
@@ -28,7 +28,8 @@
     "redux-thunk": "~2.0.1",
     "redux-logger": "~2.6.1",
     "redux-promise": "~0.5.1",
-    "immutable": "~3.7.6"
+    "immutable": "~3.7.6",
+    "react-immutable-proptypes": "~1.7.0"
   },
   "devDependencies": {
     "babel-cli": "6.5.1",
diff --git a/src/actions/RoomActions.js b/src/actions/RoomActions.js
index a941384..d6ea652 100644
--- a/src/actions/RoomActions.js
+++ b/src/actions/RoomActions.js
@@ -11,7 +11,13 @@ import ControlRequest from "../utils/ControlRequest";
 export default ({
     getRoomList: () => SocketActions.send(ControlRequest.roomList()),
 
-    join: (room) => SocketActions.send(ControlRequest.joinRoom(room)),
+    join: (room) => (dispatch) => {
+        dispatch({
+            type: ROOM_JOIN,
+            payload: room
+        });
+        dispatch(SocketActions.send(ControlRequest.joinRoom(room)));
+    },
 
     select: (room) => ({
         type: ROOM_SELECT,
@@ -19,7 +25,6 @@ export default ({
     }),
 
     say: (room, message) => (dispatch) => {
-        dispatch(SocketActions.send(ControlRequest.sayRoom(room, message)));
         dispatch({
             type: ROOM_SAY,
             payload: {
@@ -27,5 +32,6 @@ export default ({
                 message
             }
         });
+        dispatch(SocketActions.send(ControlRequest.sayRoom(room, message)));
     }
 });
diff --git a/src/components/RoomChatMessageList.js b/src/components/RoomChatMessageList.js
new file mode 100644
index 0000000..883c9ef
--- /dev/null
+++ b/src/components/RoomChatMessageList.js
@@ -0,0 +1,29 @@
+import React, { PropTypes } from "react";
+import ImmutablePropTypes from "react-immutable-proptypes";
+
+const RoomChatMessageList = ({ messages }) => {
+    // Append all messages in the chat room.
+    const children = [];
+    let i = 0;
+    for (const { user_name, message } of messages) {
+        children.push(
+            <li key={i} className="room-chat-message">
+                {user_name}: {message}
+            </li>
+        );
+        i++;
+    }
+
+    return (
+        <div id="room-chat-messages">
+            <ul>{children}</ul>
+        </div>
+    );
+};
+
+RoomChatMessageList.propTypes = {
+    messages: ImmutablePropTypes.list.isRequired
+};
+
+export default RoomChatMessageList;
+
diff --git a/src/components/RoomList.js b/src/components/RoomList.js
index 884c3b3..d0e720d 100644
--- a/src/components/RoomList.js
+++ b/src/components/RoomList.js
@@ -20,9 +20,6 @@ class RoomList extends React.Component {
         for (const [room_name, room_data] of rooms) {
             const onClick = (event) => {
                 roomActions.select(room_name);
-                if (!room_data.joined) {
-                    roomActions.join(room_name);
-                }
             };
 
             children.push(
diff --git a/src/containers/RoomChat.js b/src/containers/RoomChat.js
index 2c70dd1..2662a5e 100644
--- a/src/containers/RoomChat.js
+++ b/src/containers/RoomChat.js
@@ -1,42 +1,73 @@
 import React, { PropTypes } from "react";
-import { connect } from "react-redux";
 
-import RoomActions from "../actions/RoomActions";
 import RoomChatForm from "../components/RoomChatForm";
+import RoomChatMessageList from "../components/RoomChatMessageList";
 
-const RoomChat = ({ name, data, roomActions }) => {
-    if (!name) {
-        return <div id="room-chat">Select a room</div>;
+const ID = "room-chat";
+const ID_HEADER = "room-chat-header";
+
+class RoomChat extends React.Component {
+    constructor(props) {
+        super(props);
+    }
+
+    componentDidMount() {
+        this.join_if_non_member(this.props);
+    }
+
+    componentWillReceiveProps(props) {
+        this.join_if_non_member(props);
+    }
+
+    join_if_non_member(props) {
+        const { name, room, roomActions } = props;
+        if (room && room.membership == "NonMember") {
+            roomActions.join(name);
+        }
     }
 
-    // Append all messages in the chat room.
-    const children = [];
-    let i = 0;
-    for (const { user_name, message } of data.messages) {
-        children.push(
-            <li key={i} class="message">
-                {user_name}: {message}
-            </li>
+    render_only_header(string) {
+        return (
+            <div id={ID}>
+                <div id={ID_HEADER}>
+                    {string}
+                </div>
+            </div>
         );
-        i++;
     }
 
-    return (
-        <div id="room-chat">
-            <div id="room-chat-header">{name}</div>
-            <div id="room-chat-messages">
-                <ul>{children}</ul>
+    render() {
+        const { name, room, roomActions } = this.props;
+
+        // If no room is selected, just tell the user to select one.
+        if (!name || !room) {
+            return this.render_only_header("Select a room");
+        }
+
+        switch (room.membership) {
+            case "NonMember":
+                return this.render_only_header(`Not a member of ${name}`);
+
+            case "Joining":
+                return this.render_only_header(`Joining ${name}`);
+
+            case "Leaving":
+                return this.render_only_header(`Leaving ${name}`);
+        }
+
+        // room.membership == "Member"
+        return (
+            <div id="room-chat">
+                <div id="room-chat-header">{name}</div>
+                <RoomChatMessageList messages={room.messages} />
+                <RoomChatForm name={name} say={roomActions.say} />
             </div>
-            <RoomChatForm
-                name={name}
-                say={roomActions.say}
-            />
-        </div>
-    );
-};
+        );
+    }
+}
 
 RoomChat.propTypes = {
-    data: PropTypes.object,
+    room: PropTypes.object,
     name: PropTypes.string,
     roomActions: PropTypes.object.isRequired
 };
diff --git a/src/containers/RoomsPane.js b/src/containers/RoomsPane.js
index f384a97..a4b0ed3 100644
--- a/src/containers/RoomsPane.js
+++ b/src/containers/RoomsPane.js
@@ -14,17 +14,18 @@ class RoomsPane extends React.Component {
     }
 
     render() {
+        const { actions, rooms, selected } = this.props;
         return (
             <div id="rooms-pane">
                 <RoomList
-                    rooms={this.props.rooms}
-                    roomActions={this.props.actions.room}
-                    selected={this.props.selected}
+                    rooms={rooms}
+                    roomActions={actions.room}
+                    selected={selected}
                 />
                 <RoomChat
-                    name={this.props.selected}
-                    data={this.props.rooms.get(this.props.selected)}
-                    roomActions={this.props.actions.room}
+                    name={selected}
+                    room={rooms.get(selected)}
+                    roomActions={actions.room}
                 />
             </div>
         );
diff --git a/src/reducers/rooms.js b/src/reducers/rooms.js
index 71a45b6..5a30646 100644
--- a/src/reducers/rooms.js
+++ b/src/reducers/rooms.js
@@ -43,14 +43,24 @@ const reduceRoomList = (old_rooms, room_list) => {
     return new_rooms;
 };
 
-const reduceReceiveMessage = (rooms, payload) => {
-    switch (payload.variant) {
+const reduceReceiveMessage = (rooms, { variant, data }) => {
+    switch (variant) {
+        case "JoinRoomResponse":
+        {
+            const { room_name } = data;
+            const room = rooms.get(room_name);
+            return rooms.set(room_name, {
+                ...room,
+                membership: "Member"
+            });
+        }
+
         case "RoomListResponse":
-            return reduceRoomList(rooms, payload.data.rooms);
+            return reduceRoomList(rooms, data.rooms);
 
         case "SayRoomResponse":
         {
-            const { room_name, user_name, message } = payload.data;
+            const { room_name, user_name, message } = data;
             const room_data = rooms.get(room_name);
             if (!room_data) {
                 console.log(`Error: room "${room_name} not found`);
@@ -88,10 +98,9 @@ export default (state = initialState, action) => {
 
         case ROOM_JOIN:
         {
-            const rooms = state.rooms.merge({
-                [payload]: {
-                    joined: true
-                }
+            const rooms = state.rooms.set(payload, {
+                ...state.rooms.get(payload),
+                membership: "Joining"
             });
             return {
                 ...state,
diff --git a/src/styles/styles.scss b/src/styles/styles.scss
index 806f87f..dc31882 100644
--- a/src/styles/styles.scss
+++ b/src/styles/styles.scss
@@ -58,7 +58,6 @@ main {
 
 #room-chat {
     border: solid grey 0.1em;
-    padding: 2em;
 }
 
 #room-list {
@@ -71,6 +70,35 @@ main {
 
 #room-chat {
     flex: 3;
+    display: flex;
+    flex-flow: column;
+}
+
+#room-chat-header {
+    text-align: center;
+    font-size: 1.3em;
+    padding: 0.8em;
+    border: solid grey 0.1em;
+}
+
+#room-chat-messages {
+    flex: 1;
+}
+
+#room-chat-form {
+    width: 100%;
+    border: solid grey 0.1em;
+}
+
+#room-chat-form form {
+    width: 100%;
+    display: flex;
+    flex-flow: row;
+}
+
+#room-chat-form input {
+    flex: 1;
+    padding: 0.8em;
 }
 
 #room-list-header {