Overfitting in CNN

I am training a VGG net on STL-10 dataset

I am getting Top-5 validation accuracy about 98% and Top-1 validation accuracy about 83%

But both the Top-1 and Top-5 Training accuracy is reaching 100%

Does this mean that the network is over-fitting? Or not?

Code::

def conv2d(inp,name,kshape,s):
    with tf.variable_scope(name) as scope:
        kernel = get_weights('weights',shape=kshape)
        conv = tf.nn.conv2d(inp,kernel,[1,s,s,1],'SAME')
        bias = get_bias('biases',shape=kshape[3])
        preact = tf.nn.bias_add(conv,bias)
        convlayer = tf.nn.relu(preact,name=scope.name)
    return convlayer

def maxpool(inp,name,k,s):
    return tf.nn.max_pool(inp,ksize=[1,k,k,1],strides=[1,s,s,1],padding='SAME',name=name)

def loss(logits,labels):
    labels = tf.reshape(tf.cast(labels,tf.int64),[-1])
    #print labels.get_shape().as_list(),logits.get_shape().as_list()
    cross_entropy = tf.nn.sparse_softmax_cross_entropy_with_logits(labels=labels,logits=logits,name='cross_entropy_per_example')
    cross_entropy_mean = tf.reduce_mean(cross_entropy,name='cross_entropy')
    total_loss = tf.add(tf.reduce_sum(tf.get_collection(tf.GraphKeys.REGULARIZATION_LOSSES)),cross_entropy_mean,name='total_loss')
    return total_loss

def top_1_acc(logits,true_labels):
    pred_labels = tf.argmax(logits,1)
    true_labels = tf.cast(true_labels,tf.int64)
    #print pred_labels.get_shape().as_list(),true_labels
    correct_pred = tf.cast(tf.equal(pred_labels, true_labels), tf.float32)
    accuracy = tf.reduce_mean(tf.cast(correct_pred,tf.float32))
    return accuracy

with tf.device('/gpu:0'):
    conv1 = conv2d(feed_images,'conv1',[3,3,3,64],1)
    conv2 = conv2d(conv1,'conv2',[3,3,64,64],1)
    pool1 = maxpool(conv2,'pool1',2,2)
    #size = [N,48,48,64]
    conv3 = conv2d(pool1,'conv3',[3,3,64,128],1)
    conv4 = conv2d(conv3,'conv4',[3,3,128,128],1)
    pool2 = maxpool(conv4,'pool2',2,2)
    #size = [N,24,24,128]
    conv5 = conv2d(pool2,'conv5',[3,3,128,256],1)
    conv6 = conv2d(conv5,'conv6',[3,3,256,256],1)
    pool3 = maxpool(conv6,'pool3',2,2)
    #size = [N,12,12,256]
    conv7 = conv2d(pool3,'conv7',[3,3,256,512],1)
    conv8 = conv2d(conv7,'conv8',[3,3,512,512],1)
    pool4 = maxpool(conv8,'pool4',2,2)
    #size = [N,6,6,512]
    conv9 = conv2d(pool4,'conv9',[3,3,512,512],1)
    conv10 = conv2d(conv9,'conv10',[3,3,512,512],1)
    pool5 = maxpool(conv10,'pool5',2,2)
    #size = [N,3,3,512]
    flattened_pool5 = tf.contrib.layers.flatten(pool5)
    fc1 = tf.contrib.layers.fully_connected(flattened_pool5,1024,weights_regularizer=tf.contrib.layers.l2_regularizer(tf.constant(0.001, dtype=tf.float32)))
    dropout1 = tf.nn.dropout(fc1,keep_prob)
    fc2 = tf.contrib.layers.fully_connected(dropout1,1024,weights_regularizer=tf.contrib.layers.l2_regularizer(tf.constant(0.001, dtype=tf.float32)))
    dropout2 = tf.nn.dropout(fc2,keep_prob)
    logits = tf.contrib.layers.fully_connected(dropout2,10,activation_fn=None,weights_regularizer=tf.contrib.layers.l2_regularizer(tf.constant(0.001, dtype=tf.float32)))

    cost = loss(logits,feed_labels)

    opt_mom = tf.train.MomentumOptimizer(learning_rate=lr,momentum=0.9)
    opt = opt_mom.minimize(cost)

    acc = top_1_acc(logits,feed_labels)